Optical detector

ABSTRACT

A method of controlling pixels ( 134 ) of at least one spatial light modulator ( 114 ) is disclosed. The spatial light modulator ( 114 ) has a matrix of pixels ( 132 ). Each pixel ( 134 ) is individually controllable. The method comprises the following steps: receiving at least one image ( 331 ), ( 342 ); defining at least one image segment ( 333 ) within the image ( 331 ),( 344 ); assigning at least one gray scale value to each image segment ( 333 ),( 348 ); assigning at least one pixel ( 134 ) of the matrix of pixels ( 132 ) to each image segment ( 333 ),( 350 ); assigning a unique modulation frequency to each gray scale value assigned to the at least one image segment ( 333 ),( 352 ); controlling the at least one pixel ( 134 ) of the matrix of pixels ( 132 ) assigned to the at least one image segment ( 333 ) with the unique modulation frequency assigned to the respective image segment ( 333 ),( 354 ).

FIELD OF THE INVENTION

The present invention is based on the general ideas on optical detectorsas set forth e.g. in WO 2012/110924 A1, US 2012/0206336 A1, WO2014/097181 A1, US 2014/0291480 A1 or so far unpublished U.S.provisional applications No. 61/867,180 dated Aug. 19, 2013, 61/906,430dated Nov. 20, 2013, and 61/914,402 dated Dec. 11, 2013, as well asunpublished German patent application number 10 2014 006 279.1 datedMar. 6, 2014, European patent application number 14171759.5 dated Jun.10, 2014, international patent application number PCT/EP2014/067466dated Aug. 15, 2014 and U.S. patent application Ser. No. 14/460,540dated Aug. 15, 2014, the full content of all of which is herewithincluded by reference.

The invention relates to a method of controlling pixels of at least onespatial light modulator, a method of optical detection, specifically fordetermining a position of at least one object, a modulator device, amodulator assembly, an optical detector and a detector system. Theinvention further relates to a human-machine interface for exchanging atleast one item of information between a user and a machine, anentertainment device, a tracking system, a camera and various uses ofthe optical detector. The devices, systems, methods and uses accordingto the present invention specifically may be employed for example invarious areas of daily life, gaming, traffic technology, productiontechnology, security technology, photography such as digital photographyor video photography for arts, documentation or technical purposes,medical technology or in the sciences. Additionally or alternatively,the application may be applied in the field of mapping of spaces, suchas for generating maps of one or more rooms, one or more buildings orone or more streets. However, other applications are also possible.

PRIOR ART

A large number of optical detectors, optical sensors and photovoltaicdevices are known from the prior art. While photovoltaic devices aregenerally used to convert electromagnetic radiation, for example,ultraviolet, visible or infra-red light, into electrical signals orelectrical energy, optical detectors are generally used for picking upimage information and/or for detecting at least one optical parameter,for example, a brightness.

A large number of optical sensors which can be based generally on theuse of inorganic and/or organic sensor materials are known from theprior art. Examples of such sensors are disclosed in US 2007/0176165 A1,U.S. Pat. No. 6,995,445 B2, DE 2501124 A1, DE 3225372 A1 or else innumerous other prior art documents. To an increasing extent, inparticular for cost reasons and for reasons of large-area processing,sensors comprising at least one organic sensor material are being used,as described for example in US 2007/0176165 A1. In particular, so-calleddye solar cells are increasingly of importance here, which are describedgenerally, for example in WO 2009/013282 A1.

As a further example, WO 2013/144177 A1 discloses quinolinium dyeshaving a fluorinated counter anion, an electrode layer which comprises aporous film made of oxide semiconductor fine particles sensitized withthese kinds of quinolinium dyes having a fluorinated counter anion, aphotoelectric conversion device which comprises such a kind of electrodelayer, and a dye sensitized solar cell which comprises such aphotoelectric conversion device.

A large number of detectors for detecting at least one object are knownon the basis of such optical sensors. Such detectors can be embodied indiverse ways, depending on the respective purpose of use. Examples ofsuch detectors are imaging devices, for example, cameras and/ormicroscopes. High-resolution confocal microscopes are known, forexample, which can be used in particular in the field of medicaltechnology and biology in order to examine biological samples with highoptical resolution. Further examples of detectors for opticallydetecting at least one object are distance measuring devices based, forexample, on propagation time methods of corresponding optical signals,for example laser pulses. Further examples of detectors for opticallydetecting objects are triangulation systems, by means of which distancemeasurements can likewise be carried out.

In US 2007/0080925 A1, a low power consumption display device isdisclosed. Therein, photoactive layers are utilized that both respond toelectrical energy to allow a display device to display information andthat generate electrical energy in response to incident radiation.Display pixels of a single display device may be divided into displayingand generating pixels. The displaying pixels may display information andthe generating pixels may generate electrical energy. The generatedelectrical energy may be used to provide power to drive an image.

In EP 1 667 246 A1, a sensor element capable of sensing more than onespectral band of electromagnetic radiation with the same spatiallocation is disclosed. The element consists of a stack of sub-elementseach capable of sensing different spectral bands of electromagneticradiation. The sub-elements each contain a non-silicon semiconductorwhere the non-silicon semiconductor in each sub-element is sensitive toand/or has been sensitized to be sensitive to different spectral bandsof electromagnetic radiation.

In WO 2012/110924 A1, the content of which is herewith included byreference, a detector for optically detecting at least one object isproposed. The detector comprises at least one optical sensor. Theoptical sensor has at least one sensor region. The optical sensor isdesigned to generate at least one sensor signal in a manner dependent onan illumination of the sensor region. The sensor signal, given the sametotal power of the illumination, is dependent on a geometry of theillumination, in particular on a beam cross section of the illuminationon the sensor area. The detector furthermore has at least one evaluationdevice. The evaluation device is designed to generate at least one itemof geometrical information from the sensor signal, in particular atleast one item of geometrical information about the illumination and/orthe object.

U.S. provisional applications 61/739,173, filed on Dec. 19, 2012,61/749,964, filed on Jan. 8, 2013, and 61/867,169, filed on Aug. 19,2013, and international patent application PCT/IB2013/061095, publishedunder WO2014/097181 A1, filed on Dec. 18, 2013, the full content of allof which is herewith included by reference, disclose a method and adetector for determining a position of at least one object, by using atleast one transversal optical sensor and at least one optical sensor.Specifically, the use of sensor stacks is disclosed, in order todetermine a longitudinal position of the object with a high degree ofaccuracy and without ambiguity.

European patent application number EP 13171898.3, filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses an optical detector comprising an optical sensor having asubstrate and at least one photosensitive layer setup disposed thereon.The photosensitive layer setup has at least one first electrode, atleast one second electrode and at least one photovoltaic materialsandwiched in between the first electrode and the second electrode. Thephotovoltaic material comprises at least one organic material. The firstelectrode comprises a plurality of first electrode stripes, and thesecond electrode comprises a plurality of second electrode stripes,wherein the first electrode stripes and the second electrode stripesintersect in such a way that a matrix of pixels is formed atintersections of the first electrode stripes and the second electrodestripes. The optical detector further comprises at least one readoutdevice, the readout device comprising a plurality of electricalmeasurement devices being connected to the second electrode stripes anda switching device for subsequently connecting the first electrodestripes to the electrical measurement devices.

European patent application number EP 13171900.7, also filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses a detector device for determining an orientation of at leastone object, comprising at least two beacon devices being adapted to beat least one of attached to the object, held by the object andintegrated into the object, the beacon devices each being adapted todirect light beams towards a detector, and the beacon devices havingpredetermined coordinates in a coordinate system of the object. Thedetector device further comprises at least one detector adapted todetect the light beams traveling from the beacon devices towards thedetector and at least one evaluation device, the evaluation device beingadapted to determine longitudinal coordinates of each of the beacondevices in a coordinate system of the detector. The evaluation device isfurther adapted to determine an orientation of the object in thecoordinate system of the detector by using the longitudinal coordinatesof the beacon devices.

European patent application number EP 13171901.5, filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses a detector for determining a position of at least one object.The detector comprises at least one optical sensor being adapted todetect a light beam traveling from the object towards the detector, theoptical sensor having at least one matrix of pixels. The detectorfurther comprises at least one evaluation device, the evaluation devicebeing adapted to determine a number N of pixels of the optical sensorwhich are illuminated by the light beam. The evaluation device isfurther adapted to determine at least one longitudinal coordinate of theobject by using the number N of pixels which are illuminated by thelight beam.

In PCT/EP2014/067466, filed on Aug. 15, 2014, on which the presentinvention is based and the full content of which is herewith included byreference, an optical detector is proposed. The optical detectorcomprises at least one spatial light modulator being adapted to modifyat least one property of a light beam in a spatial resolved fashion. Thespatial light modulator has a matrix of pixels, each pixel beingcontrollable to individually modify the at least one optical property ofa portion of the light beam passing the pixel. The optical detectorcomprises at least one optical sensor adapted to detect the light beamafter passing the matrix of pixels of the spatial light modulator and togenerate at least one sensor signal. The optical detector comprises atleast one modulator device adapted for periodically controlling at leasttwo of the pixels with different modulation frequencies. The opticaldetector comprises at least one evaluation device adapted for performinga frequency analysis in order to determine signal components of thesensor signal for the modulation frequencies.

Despite the advantages implied by the above-mentioned devices anddetectors, specifically by the detectors disclosed in PCT/EP2014/067466,WO 2012/110924 A1, U.S. 61/739,173, U.S. 61/749,964, EP 13171898.3, EP13171900.7 and EP 13171901.5, several technical challenges remain. Thus,generally, a need exists for detectors for detecting a position of anobject in space which is both reliable and may be manufactured at lowcost. Specifically, a strong need exists for detectors having a highresolution, in order to generate images and/or information regarding aposition of an object, which may be realized at high volume and at lowcost and which, still, provide a high resolution and image quality.

Problem to be Solved

It is, therefore, an object of the present invention to provide devicesand methods facing the above-mentioned technical challenges of knowndevices and methods. Specifically, it is an object of the presentinvention to provide devices and methods which reliably may determine aposition of an object in space, preferably at a low technical effort andwith low requirements in terms of technical resources and cost.

SUMMARY OF THE INVENTION

This problem is solved by a method of controlling pixels of at least onespatial light modulator, a method of optical detection, a modulatordevice for controlling pixels of at least one spatial light modulator, amodulator assembly for spatial light modulation, an optical detector, adetector system, a human-machine interface, an entertainment device, atracking system, a scanning system, a camera and various uses of theoptical detector, with the features of the independent claims. Preferredembodiments which might be realized in an isolated fashion or in anyarbitrary combination are listed in the dependent claims.

As used in the following, the terms “have”, “comprise” or “include” orany arbitrary grammatical variations thereof are used in a non-exclusiveway. Thus, these terms may both refer to a situation in which, besidesthe feature introduced by these terms, no further features are presentin the entity described in this context and to a situation in which oneor more further features are present. As an example, the expressions “Ahas B”, “A comprises B” and “A includes B” may both refer to a situationin which, besides B, no other element is present in A (i.e. a situationin which A solely and exclusively consists of B) and to a situation inwhich, besides B, one or more further elements are present in entity A,such as element C, elements C and D or even further elements.

Further, as used in the following, the terms “preferably”, “morepreferably”, “particularly”, “more particularly”, “specifically”, “morespecifically” or similar terms are used in conjunction with optionalfeatures, without restricting alternative possibilities. Thus, featuresintroduced by these terms are optional features and are not intended torestrict the scope of the claims in any way. The invention may, as theskilled person will recognize, be performed by using alternativefeatures. Similarly, features introduced by “in an embodiment of theinvention” or similar expressions are intended to be optional features,without any restriction regarding alternative embodiments of theinvention, without any restrictions regarding the scope of the inventionand without any restriction regarding the possibility of combining thefeatures introduced in such way with other optional or non-optionalfeatures of the invention.

In a first aspect of the present invention a method of controllingpixels of at least one spatial light modulator is disclosed. The spatiallight modulator has a matrix of pixels, each pixel being individuallycontrollable. The method comprises the following steps, which may beperformed in the given order or in a different order. Further, two ormore or even all of the method steps may be performed simultaneouslyand/or overlapping in time. Further, one, two or more or even all of themethod steps may be performed repeatedly. The method may furthercomprise additional method steps. The method comprising the followingsteps:

-   -   a) receiving at least one image;    -   b) defining at least one image segment within the image;    -   c) assigning at least one gray scale value to each image        segment;    -   d) assigning at least one pixel of the matrix of pixels to each        image segment;    -   e) assigning a unique modulation frequency to each gray scale        value assigned to the at least one image segment;    -   f) controlling the at least one pixel of the matrix of pixels        assigned to the at least one image segment with the unique        modulation frequency assigned to the respective image segment.

As further used herein, a “spatial light modulator”, also referred to asa SLM, generally is a device adapted to modify at least one property,specifically at least one optical property, of a light beam in aspatially resolved fashion, specifically in at least one direction at anangle to a direction of propagation of a light beam, which may generallybe an arbitrary or suitable angle determined by the type of modulationdevice. The angle may be 90° or different to 90°, the latter of whichspecifically may be preferred for mobile applications. For example, thespatial light modulator may modify the at least one property,specifically the at least one optical property, of the light beam in aspatially resolved fashion in at least one direction perpendicular to adirection of propagation of the light beam. The spatial light modulatormay be mounted perpendicular to the light beam. For example, the spatiallight modulator may be illuminated by the light beam from a sidedirection. Thus, as an example, the spatial light modulator may beadapted to modify the at least one optical property in a planeperpendicular to a local direction of propagation of the light beam in acontrolled fashion. Thus, the spatial light modulator may be anarbitrary device which is capable of imposing some form of spatiallyvarying modulation on the light beam, preferably in at least onedirection perpendicular to the direction of propagation of the lightbeam. The spatial variation of the at least one property may be modifiedin a controlled fashion such that, at each controllable location in theplane perpendicular to the direction of propagation, the spatial lightmodulator may take at least two states which may modify the respectiveproperty of the light beam in different ways.

Spatial light modulators are generally known in the art, such as in theart of holography and/or in the art of projector devices. Simpleexamples of spatial light modulators generally known in the art areliquid crystal spatial modulators. Both transmissive and reflectiveliquid crystal spatial light modulators are known and may be used withinthe present invention. Further, micromechanical spatial light modulatorsare known based on an area of micro-mirrors which are individuallycontrollable. Thus, reflective spatial light modulators may be usedwhich are based on DLP® technology, available by Texas Instruments,having single-color or multi- or even full-color micro-mirrors. Further,micro-mirror arrays which may be used as spatial light modulators withinthe present invention are disclosed by V. Viereck et al., PhotonikInternational 2 (2009), 48-49, and/or in U.S. Pat. No. 7,677,742 B2(Hillmer et al.). Herein, micro-mirror arrays are shown which arecapable of switching micro-mirrors between a parallel and aperpendicular position relative to an optical axis. These micro-mirrorarrays generally may be used as a transparent spatial light modulator,similar to transparent spatial light modulator space on liquid crystaltechnology. The transparency of this type of spatial light modulators,however, generally is higher than the transparency of common liquidcrystal spatial light modulators. Further, spatial light modulators maybe based on other optical effects, such as acousto-optical effectsand/or electro-optical effects such as the so-called Pockels effectand/or the so-called Kerr effect. Further, one or more spatial lightmodulators may be provided which are based on the use of interferometricmodulation or IMOD technology. This technology is based on switchableinterference effects within each pixel. The latter, as an example, isavailable by Qualcomm®, under the trade name “Mirasorl™”.

Further, additionally or alternatively, the at least one spatial lightmodulator used herein may be or may comprise at least one array oftunable optical elements, such as one or more of an array offocus-tunable lenses, an area of adaptive liquid micro-lenses, an arrayof transparent microprisms. Any combination of the named arrays oftunable optical elements may be used. The tuning of the optical elementsof the array, as an example, may be performed electrically and/oroptically. As an example, one or more arrays of tunable optical elementsmay be placed in a first image plane, such as in other spatial lightmodulators like DLP, LCDs, LCOS or other SLMs. The focus of the opticalelements such as the micro-lenses and/or the refraction of the opticalelements such as the micro-prisms may be modulated. This modulation maythen be monitored by the at least one optical sensor and evaluated bythe at least one evaluation device, by performing the frequencyanalysis, such as the demodulation.

Tunable optical elements such as focus-tunable lenses provide theadditional advantage of being capable of correcting the fact thatobjects at different distances have different focal points.Focus-tunable lens arrays, as an example, are disclosed in US2014/0132724 A1. The focus-tunable lens arrays disclosed therein mayalso be used in the SLM of the optical detector according to the presentinvention. Other embodiments, however, are feasible. Further, forpotential examples of liquid micro-lens arrays, reference may be made toC. U. Murade et al., Optics Express, Vol. 20, No. 16, 18180-18187(2012). Again, other embodiments are feasible. Further, for potentialexamples of microprisms arrays, such as arrayed electrowettingmicroprisms, reference may be made to J. Heikenfeld et al., Optics &Photonics News, Jan. 2009, 20-26. Again, other embodiments ofmicroprisms may be used.

Thus, as an example, one or more spatial light modulators may be used,selected from the group consisting of: a spatial light modulator or areflective spatial light modulator. Further, as an example, one or morespatial light modulators may be used selected from the group consistingof: a spatial light modulator based on liquid crystal technology, suchas one or more liquid crystal spatial light modulators; a spatial lightmodulator based on a micromechanical system, such as a spatial lightmodulator based on a micro-mirror system, specifically a micro-mirrorarray; a spatial light modulator based on interferometric modulation; aspatial light modulator based on an acousto-optical effect; a spatiallight modulator based on an electro-optical effect, specifically basedon the Pockels-effect and/or the Kerr-effect; a spatial light modulatorcomprising at least one array of tunable optical elements, such as oneor more of an array of focus-tunable lenses, an area of adaptive liquidmicro-lenses, an array of transparent micro-prisms. Typical spatiallight modulators known in the art are adapted to modulate the spatialdistribution of the intensity of the light beam, such as in a planeperpendicular to the direction of propagation of the light beam.However, as will be outlined in further detail below, additionally oralternatively, other optical properties of the light beam may be varied,such as a phase of the light beam and/or a color of the light beam.Other potential spatial light modulators will be explained in moredetail below.

Generally, the spatial light modulator may be computer-controllable suchthat the state of variation of the at least one property of the lightbeam may be adjusted by a computer. The spatial light modulator may bean electrically addressable spatial light modulator, an opticallyaddressable spatial light modulator or any other type of spatial lightmodulator.

As outlined above, the spatial light modulator comprises a matrix ofpixels, each pixel being controllable to individually modify the atleast one optical property of a portion of the light beam passing thepixel, i.e. interacting with the pixels by passing through the pixel,being reflected by the pixel or other ways of interaction. As usedherein, a “pixel” thus generally refers to a unitary element of thespatial light modulator adapted to modify the at least one opticalproperty of the portion of the light beam passing the pixel.Consequently, a pixel may be the smallest unit of the spatial lightmodulator which is adapted to modify the at least one optical propertyof the portion of the light beam passing the pixel. As an example, eachpixel may be a liquid crystal cell and/or a micro-mirror. Each pixel isindividually controllable. For example, each of the pixels may compriseat least one micro-mirror.

As used herein, the term “control” generally refers to the fact that theway the pixel modifies the at least one optical property may be adjustedto assume at least two different states. The adjustment may take placeby any type of control, preferably by electrical adjustment. Thus,preferably, each pixel may be individually addressable electrically inorder to adjust the state of the respective pixel, such as by applying aspecific voltage and/or a specific electric current to the pixel.

As further used herein, the term “individually” generally refers to thefact that one pixel of the matrix may be addressed at leastsubstantially independently from addressing other pixels, such that astate of the pixel and, thus, the way the respective pixel influencesthe respective portion of the light beam, may be adjusted independentlyfrom an actual state of one or more or even ail of the other pixels.

As used herein, “receiving at least one image” generally refers to thefact of that at least one image is at least one of provided, recorded,accepted, read in and obtained. Thus, for example, the at least oneimage may be provided from a data storage and/or an imaging device orthe like, e.g. the at least one image may be provided by a CMOS and/orCCD and/or other pixelated image sensor. The at least one image may beat least one regular two-dimensional image of a scene and/or at leastone object. The at least one image may be or may comprise at least onemonochrome image and/or at least one multi-chrome image and/or at leastone full-color image. Further, the at least one image may be or maycomprise a single image or may comprise a series of images.

As used herein, “at least one image segment” refers to at least aportion and/or at least one area and/or at least one section of theimage. Specifically, the at least one image segment may correspond to ascene and/or at least one object or parts thereof. For example, the atleast one image may comprise at least one area corresponding to the atleast one scene and/or the at least one object or to parts thereof. Theat least one image may comprise two or more image segments. As usedherein, “defining at least one image segment” refers to selecting and/orchoosing and/or identifying at least a portion and/or at least one areaand/or at least one section within the image.

As used herein, the term “at least one gray scale value” refers to grayscale values or gray levels (these terms are generally and hereinafterused synonymously), i.e. different brightness levels of one or morecolors. In principle, however, the term gray level or gray scale valueshould in this case be interpreted broadly and, for example, alsoencompasses different brightness levels. A gray scale value may bebetween black (where in the case of a chromatic color “black” shouldcorrespondingly be understood to mean the darkest level) and white(where in the case of a chromatic color “white” should correspondinglybe understood to mean the lightest level). Gray scale values may becolor values and/or gray values.

As used herein, “assigning at least one gray value” refers to selectingand/or determining a gray scale value for each image segment. Inparticular, the at least one image may be encoded as a gray scale image.The gray values may be assigned in discrete steps between these blackand white limit values. For example, the gray values may be assigned ingray-level steps with a constant, predefined spacing from black towhite. A discrete number of possible gray-scale values may bepredefined. Thus, for example, in case the image comprises two imagesegments, to each of the two image segments at least one gray valuedifferent to the gray value of the other image segment may be assigned.

As used herein, “assigning at least one pixel to each image segment”refers to matching at least one pixel of the spatial light modulatorwith at least one image segment. Each pixel may be matched individuallyto the image segments and/or a group of pixels, e.g. at least twopixels, may be matched together to the image segments. Thereby,optionally, the image and/or the image segments are mapped onto thematrix of pixels. Preferably, the at least one image is pixelated suchthat the image is fully matched to the matrix of pixels, therebycreating a pixelated image.

As used herein, “assigning a unique modulation frequency” refers tomatching at least one frequency with at least one gray scale value. Asused herein, the term “unique modulation frequency” generally refers toone or both of a frequency f of a modulation and a phase φ of modulationof the control of the pixels. Thus, one or both of the frequency and/orthe phase of the periodic control or modulation may be used for encodingand/or decoding optical information, as will be discussed in furtherdetail below. Assigning the unique modulation frequency to at least onegray scale value may be based on a predetermined relationship betweenthe gray scale value and the unique modulation frequency. In particular,a look-up table may be used. The look-up table may comprise a list ofgray scale values and corresponding unique modulation frequencies.

The term “controlling” comprises selecting each individual pixel and/ora group of pixels and changing a state of the selected pixel and/orgroup of pixels. A control may be periodically and in particularlyindividually. Switching between at least two different states of therespective pixel may be performed periodically, wherein the at least twodifferent states of the respective pixel differ with regard to their wayof interacting with the portion of the light beam passing the pixel and,thus, differ with regard to their degree or way of modifying the portionof the light beam passing the pixels. The unique modulation frequencygenerally is selected from the group consisting of the frequency and/orthe phase of the periodic switching between the at least two states ofthe respective pixel. The switching generally may be a stepwiseswitching or digital switching or may be a continuous switching in whichthe state of the respective pixel is continuously changed between afirst state and a second state. As a most common example, the pixels mayperiodically be switched on or off at the respective modulationfrequencies, i.e. at a specific frequency f and/or at a specific phasecp.

Step f) may comprise the following substeps:

-   -   f1. assigning a counter threshold value to the unique modulation        frequency;    -   f2. incrementing a counter variable in a stepwise fashion at a        predetermined maximum frequency until the threshold value is        reached or exceeded;    -   f3. changing a state of the pixel.

The substeps may be performed in the given order or in a differentorder. Further, two or more or even all of the substeps may be performedsimultaneously and/or overlapping in time. Further, one, two or more oreven all of the substeps may be performed repeatedly. The step f) mayfurther comprise additional method steps.

As used herein, the term “counter variable” refers to an integer numberwhich may be incremented in a stepwise fashion. As used herein, the term“counter threshold” refers to a specified and/or predetermined thresholdfor the counter variable. In case the counter variable exceeds thecounter threshold, a state of the pixel may be changed. Thepredetermined maximum frequency may be a maximum frequency f₀ forchanging the state of the pixel resulting in a maximum light frequencyf₀/2 for the area of the beam modulated by the pixel. For example, for alight-dark change of a pixel, two changes, firstly to light and secondlyto dark, of the pixel may be necessary. The counter may be increasedwith respect to a scanning time T_(A)1/f₀. The scanning time may be atime required for processing one image within one image buffer, inparticular for performing method steps a)-f), and an adjustable delaytime, e.g. a time required for adjustments. For example, the countervariable may be increased in intervals of the scanning time and/or inintervals of multiple scanning times. A low threshold may result in ahigh frequency, and thus a short time interval, of changing a state ofthe pixel. A high threshold may result in a low frequency, and thus along time interval, of changing the pixel state, whereas an actualduration may be set by selecting f₀. A lowest threshold may refer to asingle interval of the scanning time.

Feasible unique modulation frequencies f_(n) for changing the state ofthe pixel may be determined by f_(n)=f₀/2n, wherein n is a nonzerointeger number. For example f₀ may be 24 kHz. Thus, it may be possibleto change a pixel state with a maximum frequency of 12 kHz. A totalnumber of gray scale values may depend on the total number of thefeasible unique frequencies. Feasible frequencies may be above a minimumfrequency. The minimum frequency may be a frequency above which twoneighboring feasible frequencies are distinguishable and/or resolvable.A feasible frequency may have to neighboring feasible frequencies adistance which is equal a minimum distance or exceeds a minimumdistance.

Each pixel of the spatial light modulator may have at least two states.In step f), the pixel may be switched from a first state to a secondstate or vice versa. The actual state of the pixel may be adjustable ina controlled fashion, wherein the at least two states, for each pixel,differ with regard to their interaction of the respective pixel with theportion of the light beam passing the respective pixel, such asdiffering with regard to one or more of the absorption, thetransmission, the reflection, the phase change or any other type ofinteraction of the pixel with the portion of the light beam. Forexample, a first state of the pixel may be an off-state and a secondstate of the pixel may be an on-state. In case the pixel is in theoff-state the portion of light is prevented from proceeding towards e.g.an optical sensor, which will be described in detail above. In theon-state, the light reflected by the pixel may proceed towards theoptical detector.

As outlined above, the maximum frequency given by the spatial lightmodulator may limit the number of feasible unique frequencies. Feasibleunique modulation frequencies for changing the state of the pixel may,as an example, be determined by using one, two, three or more Walshfunctions, specifically a Walsh system. As used herein and as describedin further detail under https://en.wikipedia.org/wiki/Walsh_function,the term “Walsh function” generally refers to a discrete, digitalcounterpart of a continuous, analog system of trigonometric functions onthe unit interval. Unlike trigonometric functions, Walsh functionsgenerally are only piecewise-continuous, and, in fact, are piecewiseconstant. The functions generally take the values −1 and +1 only, onsub-intervals defined by dyadic fractions. Walsh functions generallyform a complete, orthonormal set of functions, an orthonormal basis inHilbert space L² [0, 1] of the square-integrable functions on the unitinterval. Both generally are systems of bounded functions. Bothtrigonometric systems and Walsh systems generally admit naturalextension by periodicity from the unit interval to the real line.Furthermore, both Fourier analysis on the unit interval (Fourier series)and on the real line (Fourier transform) generally have their digitalcounterparts defined via Walsh system, the Walsh series analogous to theFourier series, and the Hadamard transform analogous to the FourierTransform. Walsh functions, series, and transforms find variousapplications in physics and engineering, especially in digital signalprocessing.

Using Walsh functions enables availability of a higher number offeasible unique modulation frequencies for changing the state of thepixel compared to using integer divisions as described above, having thesame maximum frequency given by the spatial light modulator. Thus, itmay be possible using spatial light modulators having a low maximumfrequency, e.g. a spatial light modulator with a maximum frequency of 2kHz.

In step e) to each gray scale value one Walsh function may be assignedto the at least one image segment. In case a plurality of segments isdefined in step b), an appropriate set of Walsh functions may beselected. The Walsh functions may be selected taking into account thetotal number of functions needed and noise between used Walsh functions,wherein the total number of functions needed may correspond to thenumber of segments defined. Preferably, neighboring Walsh functions mayhave as little as possible noise. In addition, Walsh transformation mayuse the entire spectral range such that less noise compared to Fouriertransformation between frequencies may occur. In order to be robustagainst disturbances, Walsh functions may be selected to have a longplateau and thus few zero crossings.

In step f) the at least one pixel may be controlled with a Walshfunction as unique modulation frequency. As outlined above, a pixel mayhave two states. In case of using integer divisions as described above,the state of the pixel may be switched from a first state to a secondstate or vice versa such as from an on to off state or from an off to onstate. In case of using Walsh functions the state of the pixel may varynot only between an on or off state but the state of the pixel may beswitched according to a pattern given by the certain Walsh function. Forexample, within a period, e.g. a certain time interval allowing fivechanges of the pixel state, the state of the pixel may vary according tooff, off, on, on, on. Other patterns may be feasible of course.

As outlined above, gray scale values may be color values and/or grayvalues.

Step a) may comprise providing a sequence of images. As used herein, “asequence of images” refers to the fact that at least two images arereceived in step a). Steps b)-f) may be repeated for each image of thesequence of images. The sequence of images may comprise a video.

Step a) may comprise providing the at least one image to a modulatordevice, wherein steps b)-f) may be performed by the modulator device.With respect to the modulator device, reference can be made to thedescription of a modulator device given below.

Step a) may comprise buffering the at least one image in at least oneimage buffer of the modulator device. As used herein, the term “imagebuffer” refers to a data storage device adapted to receive the at leastone image. The image buffer may be adapted to store the at least oneimage for a certain time. The image buffer may be adapted to provide theat least one image to further devices of the modulator device, inparticular for performing method steps b) to f). In step a) at least twoimage buffers may be used. The image buffers may comprise a first imagebuffer and a second image buffer, wherein the first image buffer and thesecond image buffer may be selected from the group consisting of anactive image buffer and a non active image buffer. The at least oneimage may be buffered in one or both of the non-active image buffer andthe active image buffer. The non-active image buffer may be selected tofurther evaluate the at least one image buffered within the active imagebuffer, wherein at least a second image may be received and may bebuffered in the active image buffer while evaluating the at least oneimage buffered within the active image buffer. Thus, by using at leasttwo image buffers it may be possible to receive a plurality of images atthe same time or within a short sequence of time. Thus, it is possibleto read in a plurality of images at high speed. A frame rate to read inthe plurality of images may be between 20 and 250 Hz, preferably between50 and 200 Hz, more preferably between 80 and 120 Hz, such as 100 Hz.Typically, the frame rate may be limited by and/or may depend on thestorage bandwidth of the image buffer and/or other technical factors,such as a gate run time of an FPGA or the like. By using hardware havinga higher degree of sophistication, however, such as anapplication-specific integrated circuit (ASIC) and/or a VLSI-IC. Forexample, the frame rate may correspond and/or may be a multiple of animage output of an imaging device, for example an imaging camera, fromwhich the images are received.

As outlined above, each of the pixels may comprise at least onemicro-mirror.

In a further aspect of the present invention, a method of opticaldetection is disclosed, specifically a method for determining a positionof at least one object. The method comprises the following steps, whichmay be performed in the given order or in a different order. Further,two or more or even all of the method steps may be performedsimultaneously and/or overlapping in time. Further, one, two or more oreven all of the method steps may be performed repeatedly. The method mayfurther comprise additional method steps. The method comprises thefollowing method steps:

-   -   modifying at least one property of a light beam in a spatially        resolved fashion by using at least one spatial light modulator,        the spatial light modulator having a matrix of pixels, each        pixel being controllable to individually modify the at least one        optical property of a portion of the light beam passing the        pixel, wherein the method of controlling pixels as disclosed        above is used;    -   detecting the light beam after passing the matrix of pixels of        the spatial light modulator by using at least one optical sensor        and for generating at least one sensor signal;    -   periodically controlling at least two of the pixels with        different frequencies by using at least one modulator device;        and    -   performing a frequency analysis by using at least one evaluation        device and to determining signal components of the sensor signal        for the control frequencies.

The method preferably may be performed by using the optical detectoraccording to the present invention, such as disclosed in one or more ofthe embodiments given below. Thus, with regard to definitions andpotential embodiments of the method, reference may be made to theoptical detector. Still, other embodiments are feasible. Further, themethod of controlling pixels according to the present invention is used.Thus, with regard to definitions and potential embodiments of the methodof optical detection, reference may be made to the method given below.Still, other embodiments are feasible.

In a further aspect of the invention a modulator device for controllingpixels of at least one spatial light modulator is disclosed. The spatiallight modulator has a matrix of pixels, each pixel being individuallycontrollable. The modulator device comprising:

-   -   a) at least one receiving device adapted for receiving at least        one image;    -   b) at least one image segment definition device adapted for        defining at least one image segment within the image;    -   c) at least one gray scale value assigning device adapted for        assigning at least one gray scale value to each image segment;    -   d) at least one pixel assigning device adapted for assigning at        least one pixel of the matrix of pixels to each image segment;    -   e) at least one frequency assigning device adapted for assigning        a unique modulation frequency to each gray scale value assigned        to the at least one image segment;    -   f) at least one controlling device adapted for controlling the        at least one pixel of the matrix of pixels assigned to the at        least one image segment with the unique modulation frequency        assigned to the respective image segment.

The modulator device may be adapted to perform a method of controllingpixels according to the present invention. Further, the modulator devicemay be used in the method for optical detection according to the presentinvention. With respect to definitions and embodiments, reference can bemade to definitions and embodiments of the method for controlling pixelsand the method of optical detection given above, and to definitions andembodiments of the devices given below.

As used within the present invention, a “modulator device” generallyrefers to a device which is adapted to control two or more or even allof the pixels of the matrix, in order to adjust the respective pixels toassume one out of at least two different states for each pixel, eachstate having a specific type of interaction of the pixel with theportion of the light beam passing the respective pixel. Thus, as anexample, the modulator device may be adapted to selectively apply twodifferent types of voltages and/or at least two different types ofelectric currents to each of the pixels controlled by the modulatordevice.

The at least one modulator device is adapted for periodicallycontrolling at least two of the pixels, preferably more of the pixels oreven all of the pixels of the matrix with different modulationfrequencies.

As used herein, “at least one receiving device” generally is a deviceadapted to receive at least one image. In particular, the at least onereceiving device is adapted to perform method step a) as disclosedabove. As outlined above with respect to the method for controllingpixels, the term “receiving at least one image” generally refers to thefact of that at least one image is at least one of provided, recorded,accepted and obtained. A frequency for receiving the at least one imagemay be between 60 and 120 Hz. The receiving device may comprise a portfor receiving or transferring the image, e.g. an LCD port.

The at least one receiving device may be connected or incorporate atleast one data storage device which comprises the at least one image.Additionally or alternatively, the modulator device may be connected orincorporate an imaging device or the like, e.g. a CMOS, which is adaptedto provide the at least one image.

The receiving device may comprise at least one image buffer. Preferably,the receiving device may comprise at least two image buffers. The imagebuffers may comprise a first image buffer and a second image buffer,wherein the first image buffer and the second image buffer may beselected from the group consisting of an active image buffer and a nonactive image buffer. The receiving device may be adapted to buffer theat least one image in one or both of the non-active image buffer and theactive image buffer. The receiving device may be adapted to select thenon-active image buffer to further evaluate the at least one imagebuffered within the active image buffer, wherein the receiving devicemay be adapted to receive and buffer at least a second image in theactive image buffer while evaluating the at least one image bufferedwithin the active image buffer.

The receiving device may be adapted to receive a sequence of images. Afirst image of the sequence of images may be buffered within the firstimage buffer. The first image may be processed further, in particular byperforming method steps b) to f) of the method of controlling pixels asdisclosed above, and/or may be transferred to a further device of themodulation device. While processing the first image, the second imagemay be buffered within the second image buffer. The modulation devicemay comprise additional buffers to buffer a plurality of images.Processing of the second image may be performed during or after thefirst image has been processed. The frequency for receiving the at leastone image is between 60 and 120 Hz. One or more of the receiving device,the image segment definition device, the gray scale value assigningdevice, the pixel assigning device and the frequency assigning devicemay be fully or partially comprised by one or more of: a memory device,a processor, a programmable logic such as an FPGA, DLPC, CPLD, customVLSI-IC, and/or ASIC

As used herein, “at least one image segment definition device” generallyis a device adapted to define at least one image segment within theimage. In particular, the at least one receiving device is adapted toperform method step b) as disclosed above. The image segment definitiondevice may be adapted to select and/or choose and/or identify at leastone image segment within the image.

As used herein, “at least one gray scale value assigning device”generally is a device adapted for assigning at least one gray scalevalue to each image segment. In particular, the at least one receivingdevice is adapted to perform method step c) as disclosed above. The grayscale value assigning device may be adapted to assign to each of thedefined segments at least one gray scale value. The gray scale valueassigning device may be adapted to transfer and/or encode the image intoa gray scale image.

As outlined above, the term “gray scale value” refers to brightnesslevels, e.g. of a color, too. Thus, in an embodiment, a plurality ofmodulator devices may be used. Each modulator device of the plurality ofmodulator devices may be adapted to encode the provided image in atleast a specific color. One or more of the pixel assigning device, thefrequency assigning device and the controlling device may be adapted todetermine and/or identify to which modulator device a gray scale imagebelongs. Thus, it may be possible to control a plurality of modulatordevices, e.g. with one or more of pixel assigning device, frequencyassigning device and controlling device in common.

As used herein, “at least one pixel assigning device” generally is adevice adapted for assigning at least one pixel of the matrix of pixelsto each image segment. In particular, the at least one receiving deviceis adapted to perform method step d) as disclosed above. The at leastone pixel assigning device may be adapted to perform a matching of thepixels of the spatial light modulator and the at least one image.

As used herein, “at least one frequency assigning device” generally is adevice adapted for assigning a unique modulation frequency to each grayscale value assigned to the at least one image segment. In particular,the at least one receiving device is adapted to perform method step e)as disclosed above. The frequency assigning device may be adapted toassign the unique modulation frequency based on a predeterminedrelationship between the gray scale value and the unique modulationfrequency.

Assigning the unique modulation frequency to at least one gray scalevalue may be based on a predetermined relationship between the grayscale value and the unique modulation frequency. In particular, alook-up table may be used. The look-up table may comprise a list of grayscale values and corresponding unique modulation frequencies.

The controlling device may comprise at least one oscillator. The termoscillator generally refers to a timing source adapted to control eachpixel with respect to the unique modulation frequency.

The modulator device may be adapted such that each of the pixels iscontrolled at a unique modulation frequency. The controlling device maybe connected to the spatial light modulator. For example, thecontrolling device and the spatial light modulator may be connectedelectrically, such as in a wire-bound fashion and/or wirelessly.However, other connections may be feasible. Specifically, thecontrolling device may be connected to the pixels of the spatial lightmodulator, such that the pixels are controllable by the controllingdevice.

The spatial light modulator may require a specific data format, such asdata strings, e.g. a 64 bit or a 128 bit string. The controlling devicemay be adapted to generate at least one signal, e.g. a data string, inthe required specific data format, which can be read in and/or processedfurther by the spatial light modulator. The required data string may benot large enough to allow to control all pixels of the spatial lightmodulator. Thus, the signal of the controlling device may be read out inshorter strings similar to a cathode ray tube (CRT) screen, e.g. line-or blockwise with a line and/or a blocksize which may be determined bythe type of matrix of pixels of the digital micro-mirror device.

The controlling device may be adapted to assign a counter thresholdvalue to the unique modulation frequency, wherein the controlling devicemay be further adapted to increment a counter variable in a stepwisefashion at the predetermined maximum frequency f₀ until the thresholdvalue is reached or exceeded and to change a state of the pixel. Thepredetermined maximum frequency may be a maximum frequency f₀ forchanging the state of the pixel generating a light frequency of f₀/2.Feasible unique modulation frequencies f_(n) for changing the state ofthe pixel are determined by f_(n)=f₀/2n, wherein n is a nonzero integernumber.

The spatial light modulator may be a spatial light modulator based onmicro-mirror or micro-cavity technology, such as the micro-mirror DLP®technology available by Texas Instruments. The SLM based on micro-mirroror micro-cavity technology may have single-color or multi- or evenfull-color micro-mirrors or micro-cavities. The micro-mirrors ormicro-cavities can be switched into two different positions or statessuch that the micro-mirrors may depict black and white pictures. Themaximum frequency for changing the pixel state may be f₀=24 kHzresulting in a light frequency of f₀/2=12 kHz. The total number of grayscale values assignable by the gray scale value assigning device maydepend on the total number of the feasible unique frequencies. In thisembodiment, pixels of a digital micro-mirror or micro-cavity device maybe controlled by a DLP-controller, which may be an FPGA in combinationwith a memory device comprising DLP-firmware and/or a VLSI-IC which mayoptionally be combined with a second FPGA, CPLD, ASIC or VLSI-IC fordata formatting.

The modulator device may be adapted for periodically modulating the atleast two pixels with different unique modulation frequencies. In oneembodiment, the spatial light modulator may be a bipolar spatial lightmodulator, wherein each pixel has at least two states. The controllingdevice may be adapted to switch the pixel from a first state to a secondstate or vice versa. In particular, the controlling device may beadapted to switch the pixel from the first state to the second stateperiodically with the unique modulation frequency.

The modulation device may be connected to at least one evaluationdevice, in particular to the evaluation device described in furtherdetail below. Thus, the evaluation device may be adapted to receiveand/or exchange data, such as information about a set of uniquemodulation frequencies and/or about at least one image received by themodulator device etc., with the modulator device. Further, themodulation device may be connected to at least one optical sensor, e.g.an optical sensor comprising a CMOS-chip, and/or the spatial lightmodulator and/or to one or more output devices.

In a further aspect, a modulator assembly for spatial light modulationis disclosed. The modulator assembly comprises at least one spatiallight modulator and at least one modulator device as disclosed anddescribed in detail above. With respect to definitions and embodiments,reference can be made to definitions and embodiments of the methods anddevices given above, and to further definitions and embodiments of thedevices given below.

The at least one spatial light modulator may be adapted to modify atleast one property of a light beam in a spatially resolved fashion. Thespatial light modulator may have a matrix of pixels, each pixel beingcontrollable to individually modify at least one optical property of aportion of the light beam passing the pixel. The at least one modulatordevice may be adapted for periodically controlling at least two of thepixels with different modulation frequencies.

As used herein, a “light beam” generally is an amount of light travelinginto more or less the same direction. Thus, preferably, a light beam mayrefer to a Gaussian light beam, as known to the skilled person. However,other light beams, such as non-Gaussian light beams, are possible. Asoutlined in further detail below, the light beam may be emitted and/orreflected by an object. Further, the light beam may be reflected and/oremitted by at least one beacon device which preferably may be one ormore of attached or integrated into an object.

As further used herein, the term “modify at least one property of thelight beam” generally refers to the fact that the pixel is capable ofchanging the at least one property of the light beam for the portion ofthe light beam passing the pixel by at least some degree. Preferably,the degree of change of the property may be adjusted to assume at leasttwo different values including the possibility that one of the at leasttwo different values implies unchanged passing of the portion of thelight beam. The modification of the at least one property of the lightbeam may take place in any feasible way by any feasible interaction ofthe pixels with the light beam, including one or more of absorption,transmission, reflection, phase change or other types of opticalinteraction. Thus, as an example, each pixel may take at least twodifferent states, wherein the actual state of the pixel may beadjustable in a controlled fashion, wherein the at least two states, foreach pixel, differ with regard to their interaction of the respectivepixel with the portion of the light beam passing the respective pixel,such as differing with regard to one or more of the absorption, thetransmission, the reflection, the phase change or any other type ofinteraction of the pixel with the portion of the light beam.

Thus, a “pixel” generally may refer to a minimum uniform unit of thespatial light modulator adapted to modify the at least one property of aportion of the light beam in a controlled fashion. As an example, eachpixel may have an area of interaction with the light beam, also referredto as a pixel area, of 1 μm² to 5 000 000 μm², preferably 100 μm² to 4000 000 μm², preferably 1 000 μm² to 1 000 000 μm² and more preferably 2500 μm² to 50 000 μm². Still, other embodiments are feasible.

The expression “matrix” generally refers to an arrangement of aplurality of the pixels in space, which may be a linear arrangement oran areal arrangement. Thus, generally, the matrix preferably may beselected from the group consisting of a one-dimensional matrix and atwo-dimensional matrix. The pixels of the matrix may be arranged to forma regular pattern, which may be at least one of a rectangular pattern, apolygonal pattern, a hexagonal pattern, a circular pattern or anothertype of pattern. Thus, as an example, the pixels of the matrix may bearranged independently equidistantly in each dimension of a Cartesiancoordinate system and/or in a polar coordinate system. As an example,the matrix may comprise 100 to 100 000 000 pixels, preferably 1 000 to 1000 000 pixels and, more preferably, 10 000 to 500 000 pixels. Mostpreferably, the matrix is a rectangular matrix having pixels arranged inrows and columns.

As will be outlined in further detail below, the pixels of the matrixmay be identical or may vary. Thus, as an example, all pixels of thematrix may have the same spectral properties and/or may have the samestates. As an example, each pixel may have an on-state and an off-state,wherein the light, in the on-state, may pass through the pixel or may bereflected by the pixel into a direction of passing or a direction of theoptical sensor, and wherein, in the off-state, the light is blocked orattenuated by the pixel or is reflected into a blocking direction, suchas to a beam dump away from the optical sensor. Further, the pixels mayhave differing properties, such as differing states. As an example whichwill be outlined in further detail below, the pixels may be coloredpixels including differing spectral properties, such as differing filterproperties with regard to a transmission wavelength and/or a reflectionwavelength of the light. Thus, as an example, the matrix may be a matrixhaving red, green and blue pixels or other types of pixels havingdifferent colors. As an example, the SLM may be a full-color SLM such asa full-color liquid crystal device and/or a micro-mirror device havingmirrors of differing spectral properties.

In a further aspect of the present invention, an optical detector isdisclosed. The optical detector comprises:

-   -   at least one modulator assembly according to the modulator        assembly described above;    -   at least one optical sensor adapted to detect the light beam        after passing the matrix of pixels of the spatial light        modulator and to generate at least one sensor signal;    -   at least one modulator device adapted for periodically        controlling at least two of the pixels with different modulation        frequencies;    -   at least one evaluation device adapted for performing a        frequency analysis in order to determine signal components of        the sensor signal for unique modulation frequencies.

The modulator assembly comprises the modulator device according to thepresent invention. With respect to definitions and embodiments,reference can be made to definitions and embodiments of the methods anddevices given above, and to definitions and embodiments of the devicesgiven below.

As used herein, an “optical detector” or, in the following, simplyreferred to as a “detector”, generally refers to a device which iscapable of generating at least one detector signal and/or at least oneimage, in response to an illumination by one or more light sourcesand/or in response to optical properties of a surrounding of thedetector. Thus, the detector may be an arbitrary device adapted forperforming at least one of an optical measurement and imaging process.

Specifically, as will be outlined in further detail below, the opticaldetector may be a detector for determining a position of at least oneobject. As used herein, the term position generally refers to at leastone item of information regarding a location and/or orientation of theobject and/or at least one part of the object in space. Thus, the atleast one item of information may imply at least one distance between atleast one point of the object and the at least one detector. As will beoutlined in further detail below, the distance may be a longitudinalcoordinate or may contribute to determining a longitudinal coordinate ofthe point of the object. Additionally or alternatively, one or moreother items of information regarding the location and/or orientation ofthe object and/or at least one part of the object may be determined. Asan example, at least one transversal coordinate of the object and/or atleast one part of the object may be determined. Thus, the position ofthe object may imply at least one longitudinal coordinate of the objectand/or at least one part of the object. Additionally or alternatively,the position of the object may imply at least one transversal coordinateof the object and/or at least one part of the object. Additionally oralternatively, the position of the object may imply at least oneorientation information of the object, indicating an orientation of theobject in space.

As further used herein, the term “optical sensor” generally refers to alight-sensitive device for detecting a light beam and/or a portionthereof, such as for detecting an illumination and/or a light spotgenerated by a light beam. The optical sensor, in conjunction with theevaluation device, may be adapted, as outlined in further detail below,to determine at least one longitudinal coordinate of the object and/orof at least one part of the object, such as at least one part of theobject from which the at least one light beam travels towards thedetector.

The optical detector may comprise one or more optical sensors. In case aplurality of optical sensors is comprised, the optical sensors may beidentical or may be different such that at least two different types ofoptical sensors may be comprised. As outlined in further detail below,the at least one optical sensor may comprise at least one of aninorganic optical sensor and an organic optical sensor. As used herein,an organic optical sensor generally refers to an optical sensor havingat least one organic material included therein, preferably at least oneorganic photosensitive material. Further, hybrid optical sensors may beused including both inorganic and organic materials.

The at least one optical sensor specifically may be or may comprise atleast one longitudinal optical sensor and/or at least one transversaloptical sensor. For potential definitions of the terms “longitudinaloptical sensor” and “transversal optical sensor”, as well as forpotential embodiments of these sensors, reference may be made, as anexample, to the at least one longitudinal optical sensor and/or to theat least one transversal optical sensor as shown in WO2014/097181 A1.Other setups are feasible.

The at least one optical sensor is adapted to detect the light beamafter passing the matrix of pixels of the spatial light modulator, i.e.after being transmitted by the spatial light modulator and/or beingreflected by the spatial light modulator. As used herein, the term“detect” generally refers to the fact that the optical sensor is adaptedto generate the at least one sensor signal depending on at least oneproperty of the light beam in directing with the optical sensor,preferably depending on an intensity of the light beam. As will beoutlined in further detail below, however, the sensor signal may,additionally or alternatively, depend on other properties of the lightbeam such as a width of the light beam. The sensor signal preferably maybe an electrical signal, such as an electrical current and/or anelectric voltage. The sensor signal may be a continuous or discontinuoussignal. Further, the sensor signal may be an analogue signal or adigital signal. Further, the optical sensor, by itself and/or inconjunction with other components of the optical detector, may beadapted to process or preprocess the detector signal, such as byfiltering and/or averaging, in order to provide a processed detectorsignal. Thus, as an example, a bandpass filter may be used in order totransmit only detector signals of a specific frequency range. Othertypes of preprocessing are feasible. In the following, when referring tothe detector signal, no difference will be made between the case inwhich the raw detector signal is used and the case in which apreprocessed detector signal is used for further evaluation.

As further used herein, the term “evaluation device” generally refers toan arbitrary device adapted to perform the named operations. Theevaluation device may contain one or more sub-devices such as one ormore of a measurement device, a frequency analyzer, preferably aphase-sensitive frequency analyzer, a Fourier analyzer, and ademodulation device. Thus, as an example, the evaluation device maycomprise at least one frequency mixing device adapted for mixing aspecific modulation frequency with the detector signal. The mixed-signalobtained this way may be filtered by using a low-pass filter in order toobtain a demodulated signal. By using a set of frequencies, demodulatedsignals for various frequencies may be generated by the evaluationdevice, thus providing a frequency analysis. The frequency analysis maybe a full frequency analysis over a range of frequency or phases or maybe a selective frequency analyzer for one, two or more predetermined oradjustable frequencies and/or phases.

As used herein, the term “frequency analysis” generally refers to thefact that the evaluation device is adapted to evaluate the detectorsignal in a frequency-selective way, thus separating the signalcomponents of the sensor signal at least two different frequenciesand/or phases, i.e. according to their frequency f and/or according totheir phase φ. Thus, the signal components may be separated according totheir frequency f and/or phase φ, the latter even in case these signalcomponents may have the same frequency f. Thus, the frequency analysisgenerally may be adapted to separate the signal components according toone or more of a frequency and a phase. Consequently, for eachmodulation frequency, one or more signal components may be determined bythe frequency analysis. Thus, generally, the frequency analysis may beperformed in a phase-sensitive way or in a non-phase-sensitive way.

The frequency analysis may take place at one, two or more differentfrequencies, thus obtaining the signal components of the sensor signalat these one, two or more different frequencies. The two or moredifferent frequencies may be discrete frequencies or may be a continuousfrequency range, such as a continuous frequency range in a frequencyinterval. Frequency analyzers generally are known in the art ofhigh-frequency electronics.

Preferably, the evaluation device is adapted to perform the frequencyanalysis for the unique modulation frequencies. Thus, preferably, theevaluation device at least is adapted to determine the frequencycomponents of the sensor signal for the different unique modulationfrequencies used by the modulator device. In fact, the modulator devicemay even fully or partially be part of the evaluation device or viceversa. Thus, as an example, one or more signal generators may beprovided which both provide the unique modulation frequencies used bythe modulator device and the frequencies for frequency analysis. As anexample, the at least one signal generated may be used both forproviding a set of unique modulation frequencies for periodicallycontrolling the at least two pixels, preferably more or even all of thepixels, and for providing the same set of unique modulation frequenciesfor frequency analysis. Thus, each unique modulation frequency of theset of unique modulation frequencies may be provided to a respectivepixel. Further, each unique modulation frequency of the set of uniquemodulation frequencies may be provided to a demodulation device of theevaluation device in order to demodulate the sensor signal with therespective unique modulation frequency, thereby obtaining a signalcomponent for the unique respective modulation frequency. Thus, a set ofsignal components may be generated by the evaluation device, each signalcomponent of the set of signal components corresponding to a respectiveunique modulation frequency of the set of unique modulation frequenciesand, thus, corresponding to a respective pixel of the matrix. Thus,preferably, the evaluation device may be adapted to establish anunambiguous correlation between each of the signal components and apixel of the matrix of pixels of the spatial light modulator. In otherwords, the evaluation device may be adapted to separate the sensorsignal provided by the at least one optical sensor into signalcomponents which are generated by the light portions passing therespective pixel and/or to assign signal components to specific pixelsof the matrix.

In case a plurality of optical sensors are provided, the evaluationdevice may be adapted to perform the above-mentioned frequency analysisfor each of the optical sensors individually or in common or may beadapted to perform the above-mentioned frequency analysis for only oneor more of the optical sensors

As will be outlined in further detail below, the evaluation device maycomprise at least one data processing device, such as at least onemicrocontroller or processor. Thus, as an example, the at least oneevaluation device may comprise at least one data processing devicehaving a software code stored thereon comprising a number of computercommands. Additionally or alternatively, the evaluation device maycomprise one or more electronic components, such as one or morefrequency mixing devices and/or one or more filters, such as one or moreband-pass filters and/or one or more low-pass filters. Thus, as anexample, the evaluation device may comprise at least one Fourieranalyzer and/or at least one lock-in amplifier or, preferably, a set oflock-in amplifiers, for performing the frequency analysis. Thus, as anexample, in case a set of modulation frequencies is provided, theevaluation device may comprise a separate lock-in amplifier for eachunique modulation frequency of the set of modulation frequencies or maycomprise one or more lock-in amplifiers adapted for performing afrequency analysis for two or more of the unique modulation frequencies,such as sequentially or simultaneously. Lock-in amplifiers of this typegenerally are known in the art.

The evaluation device may, as an example, comprise at least one Walshanalyzer adapted to perform a Walsh analysis. Thus, as used herein, theterm “Walsh analyzer” generally refers to an arbitrary device adapted orconfigured to perform a Walsh analysis. As an example, the Walshanalyzer may fully or partially be implemented in software and/orhardware. Further, the Walsh analyzer may fully or partially beintegrated into or may comprise at least one data processing device,such as at least one processor and/or at least one application-specificintegrated circuit (ASIC). The Walsh analyzer may fully or partially beintegrated into the evaluation device and/or may fully or partially beimplemented into at least one separate device. Using Walshtransformation instead of Fourier transformations or in addition toFourier transformations is specifically advantageous in view of signalprocessing and signal processing devices. Walsh transformations may beimplemented using addition and subtraction processes only, whereas usingFourier transformations a digital signal processor may be necessaryadapted to process floating point numbers. Thus, when using Walshtransformation simpler digital signal processor compared to digitalsignal processors necessary for performing Fourier transformation may beused. Thus, using Walsh functions and transformation specifically mayresult in a cost benefit.

Performance of frequency analysis may be affected by noise such thatpresence of noise may result in reconstruction errors and that noise maylimit quality of the reconstruction. Using Walsh transformations, lowerreconstruction errors may occur as compared to using Fouriertransformations.

Before performing frequency analysis, a signal may be modified byfiltering processes. Thus, the evaluation device and/or the Walshanalyzer may comprise at least one filtering device, adapted to filter asignal before performing a frequency analysis. In case the signal, inparticular the signal composed of Walsh functions, is filtered beforefrequency analysis, coefficients of the Walsh functions may be affected.Walsh functions may be distributed over the frequency domain such thatthe effect may be different on each Walsh function. This effect on theWalsh coefficients may be taken into account by calibration of eachWalsh coefficient, in particular by amplitude calibration. Thecalibration process may be performed before and/or during a measurement.In a first calibration step for each Walsh function, the reconstructionwith and without application of filtering processes may be simulated andmay be compared with the original Walsh function. In a furthercalibration step, the Walsh coefficients may be adjusted. Thecalibration process may be performed repeatedly, for example to enhancethe reconstruction quality.

The evaluation device can be connected to or may comprise at least onefurther data processing device that may be used for one or more ofdisplaying, visualizing, analyzing, distributing, communicating orfurther processing of information, such as information obtained by theoptical sensor and/or by the evaluation device. The data processingdevice, as an example, may be connected or incorporate at least one of adisplay, a projector, a monitor, an LCD, a TFT, an LED pattern, or afurther visualization device. It may further be connected or incorporateat least one of a communication device or communication interface, aconnector or a port, capable of sending encrypted or unencryptedinformation using one or more of email, text messages, telephone,bluetooth, Wi-Fi, infrared or internet interfaces, ports or connections.The data processing device, as an example, may use communicationprotocols of protocol families or suites to exchange information withthe evaluation device or further devices, wherein the communicationprotocol specifically may be one more of: TCP, IP, UDP, FTP, HTTP, IMAP,POP3, ICMP, IIOP, RMI, DCOM, SOAP, DDE, NNTP, PPP, TLS, E6, NTP, SSL,SFTP, HTTPs, Telnet, SMTP, RTPS, ACL, SCO, L2CAP, RIP, or a furtherprotocol. The protocol families or suites specifically may be one ormore of TCP/IP, IPX/SPX, X.25, AX.25, OSI, AppleTalk or a furtherprotocol family or suite. The data processing device may further beconnected or incorporate at least one of a processor, a graphicsprocessor, a CPU, an Open Multimedia Applications Platform (OMAP™), anintegrated circuit, a system on a chip such as products from the Apple Aseries or the Samsung S3C2 series, a microcontroller or microprocessor,one or more memory blocks such as ROM, RAM, EEPROM, or flash memory,timing sources such as oscillators or phase-locked loops,counter-timers, real-time timers, or power-on reset generators, voltageregulators, power management circuits, or DMA controllers. Individualunits may further be connected by buses such as AMBA buses.

The evaluation device and/or the data processing device may be connectedby or have further external interfaces or ports such as one or more ofserial or parallel interfaces or ports, USB, Centronics Port, FireWire,HDMI, Ethernet, Bluetooth, RFID, Wi-Fi, USART, or SPI, or analoginterfaces or ports such as one or more of ADCs or DACs, or astandardized interfaces or ports to further devices such as a 2D-cameradevice using an RGB-interface such as CameraLink. The evaluation deviceand/or the data processing device may further be connected by one ormore of interprocessor interfaces or ports, FPGA-FPGA-interfaces, orserial or parallel interfaces ports. The evaluation device and the dataprocessing device may further be connected to one or more of an opticaldisc drive, a CD-RW drive, a DVD+RW drive, a flash drive, a memory card,a disk drive, a hard disk drive, a solid state disk or a solid statehard disk.

The evaluation device and/or the data processing device may be connectedby or have one or more further external connectors such as one or moreof phone connectors, RCA connectors, VGA connectors, hermaphroditeconnectors, USB connectors, HDMI connectors, 8P8C connectors, BCNconnectors, IEC 60320 C14 connectors, optical fiber connectors,D-subminiature connectors, RF connectors, coaxial connectors, SCARTconnectors, XLR connectors, and/or may incorporate at least one suitablesocket for one or more of these connectors.

The evaluation device may be connected by at least one interface withthe modulation device. Thus, the evaluation device may be adapted toreceive and/or exchange data, such as information about a set of uniquemodulation frequencies and/or about at least one image received by themodulator device etc., with the modulator device. Further, theevaluation device may be connected to at least one optical sensor, e.g.an optical sensor comprising a CMOS-chip, and/or the spatial lightmodulator and/or to one or more output devices.

Possible embodiments of a single device incorporating one or more of theoptical detector according to the present invention, the evaluationdevice or the data processing device, such as incorporating one or moreof the optical sensor, optical systems, evaluation device, communicationdevice, data processing device, interfaces, system on a chip, displaydevices, or further electronic devices, are: mobile phones, personalcomputers, tablet PCs, televisions, game consoles or furtherentertainment devices. In a further embodiment, the 3D-camerafunctionality which will be outlined in further detail below may beintegrated in devices that are available with conventional 2D-digitalcameras, without a noticeable difference in the housing or appearance ofthe device, where the noticeable difference for the user may only be thefunctionality of obtaining and or processing 3D information.

Specifically, an embodiment incorporating the optical detector and/or apart thereof such as the evaluation device and/or the data processingdevice may be: a mobile phone incorporating a display device, a dataprocessing device, the optical sensor, optionally the sensor optics, andthe evaluation device, for the functionality of a 3D camera. The opticaldetector according to the present invention specifically may be suitablefor integration in entertainment devices and/or communication devicessuch as a mobile phone.

A further embodiment of the present invention may be an incorporation ofthe optical detector or a part thereof such as the evaluation deviceand/or the data processing device in a device for use in automotive, foruse in autonomous driving or for use in car safety systems such asDaimler's Intelligent Drive system, wherein, as an example, a deviceincorporating one or more of the optical sensor, optionally one or moreoptical systems, the evaluation device, optionally a communicationdevice, optionally a data processing device, optionally one or moreinterfaces, optionally a system on a chip, optionally one or moredisplay devices, or optionally further electronic devices may be part ofa vehicle, a car, a truck, a train, a bicycle, an airplane, a ship, amotorcycle. In automotive applications, the integration of the deviceinto the automotive design may necessitate the integration of theoptical sensor, optionally optics, or device at minimal visibility fromthe exterior or interior. The optical detector or a part thereof such asthe evaluation device and/or the data processing device may beespecially suitable for such integration into automotive design.

The present invention basically may use a frequency analysis forassigning frequency components to specific pixels of the spatial lightmodulator. Generally, sophisticated display technology and appropriatesophisticated spatial light modulators having a high resolution and/or ahigh quality are widely available at low cost, whereas a spatialresolution of optical sensors generally is technically challenging.Consequently, instead of using a pixelated optical sensor, the presentinvention provides the advantage of possibly using a large-area opticalsensor or an optical sensor having a low resolution, in combination witha pixelated spatial light modulator, in conjunction with assigningsignal components of the sensor signal to the respective pixels of thepixelated spatial light modulator via frequency analysis. Consequently,low cost optical sensors may be used, or optical sensors may be usedwhich may be optimized with regard to other parameters instead ofresolution, such as transparency, low noise and high signal quality orcolor. The spatial resolution and the technical challenges imposedthereby may be transferred from the optical sensor to the spatial lightmodulator.

The at least one spatial light modulator may further be adapted and/orcontrolled to provide one or more light patterns. Thus, the at least onespatial light modulator may be controlled in such a fashion that one ormore light patterns are reflected and/or transmitted towards the atleast one optical sensor, such as towards the at least one longitudinaloptical sensor. The at least one light pattern generally may be or maycomprise at least one generic light pattern and/or may be or maycomprise at least one light pattern dependent on a space or scenecaptured by the optical detector and/or may be dependent on a specificanalysis of a scene captured by the optical detector. Examples forgeneric patterns are: patterns based on fringes (see e.g. T. Peng:“Algorithms and models for 3-0 shape measurement using digital fringeprojections”, Dissertation, University of Maryland (College Park, Md.),16 Jan. 2007—available online underhttp://drum.lib.umd.edu/handle/1903/6654) and/or patterns based on graycodes (see e.g. http://en.wikipedia.org/wiki/Gray_code). These types ofpatterns are commonly used in structured light illumination based3D-recognition (see e.g.http://en.wikipedia.org/wiki/Structured-light_3D_scanner) or fringeprojection).

The spatial light modulator and the optical sensor may be spatiallyseparated, such as by establishing these components as separatecomponents of the optical detector. As an example, along an optical axisof the optical detector, the spatial light modulator may be separatedfrom the at least one optical sensor by at least 0.5 mm, preferably byat least 1 mm and, more preferably, by at least 2 mm. However, otherembodiments are feasible, such as by fully or partially integrating thespatial light modulator into the optical sensor.

The optical detector according to this basic principle of the presentinvention may be further developed by various embodiments which may beused in isolation or in any feasible combination.

Thus, as outlined above, the evaluation device may further be adapted toassign each signal component to a respective pixel in accordance withits unique modulation frequency. For further details, reference may bemade to the embodiments given above. Thus, as an example, a set ofunique modulation frequencies may be used, each unique modulationfrequency being assigned to a specific pixel of the matrix, wherein theevaluation device may be adapted to perform the frequency analysis ofthe sensor signal at least for the unique modulation frequencies of theset of unique modulation frequencies, thereby deriving the signalcomponents at least for these unique modulation frequencies. As outlinedabove, the same signal generator may be used both for the modulatordevice and for the frequency analysis. Preferably, the modulator deviceis adapted such that each of the pixels is controlled at a uniquemodulation frequency. Thus, by using unique modulation frequencies, awell-defined relationship between the modulation frequency and therespective pixel may be established such that each signal component maybe assigned to a respective pixel via the unique modulation frequency.Still, other embodiments are feasible, such as by subdividing theoptical sensor and/or the spatial light modulator into two or moreregions. Therein, each region of the spatial light modulator inconjunction with the optical sensor and/or a part thereof, may beadapted to perform the above-mentioned assignment. Thus, as an example,the set of modulation frequencies may both be provided to a first regionof the spatial light modulator and to at least one second region of thespatial light modulator. An ambiguity in the signal components of thesensor signal between the sensor signals generating from the firstregion and sensor signals generating from the second region may beresolved by other means, such as by using additional modulation.

Thus, generally, the modulator device may be adapted for controlling theat least two pixels, preferably more of the pixels or even all of thepixels of the matrix each with precisely one unique modulation frequencyor each with two or more modulation frequencies. Thus, a single pixelmay be modulated with one unique modulation frequency, two uniquemodulation frequencies or even more unique modulation frequencies. Thesetypes of multi-frequency modulation generally are known in the art ofhigh-frequency electronics.

As outlined above, the modulator device may be adapted for periodicallymodulating the at least two pixels with the different unique modulationfrequencies. More preferably, as discussed above, the modulator devicemay provide or may make use of a set of unique modulation frequencies,each unique modulation frequency of the set of unique modulationfrequencies being assigned to a specific pixel. As an example, the setof unique modulation frequencies may comprise at least two uniquemodulation frequencies, more preferably at least five unique modulationfrequencies, most preferably at least 10 unique modulation frequencies,at least 50 unique modulation frequencies, at least 100 uniquemodulation frequencies, at least 500 unique modulation frequencies or atleast 1000 unique modulation frequencies. Other embodiments arefeasible.

As outlined in further detail above, the evaluation device preferablymay be adapted for performing the frequency analysis by demodulating thesensor signal with different unique modulation frequencies. For thispurpose, the evaluation device may contain one or more demodulationdevices, such as one or more frequency mixing devices, one or morefrequency filters such as one or more low-pass filters or one or morelock-in amplifiers and/or Fourier-analyzers. The evaluation devicepreferably may be adapted to perform a discrete or continuous Fourieranalysis over a predetermined and/or adjustable range of frequencies.Further, the evaluation device preferably may comprise at least oneWalsh analyzer adapted to perform a Walsh analysis.

As discussed above, the evaluation device preferably may be adapted touse the same set of unique modulation frequencies which is also used bythe modulator device such that the modulation of the spatial lightmodulator by the modulator device and the demodulation of the sensorsignals by the evaluation device preferably take place with the same setof unique modulation frequencies.

Further preferred embodiments relate to the at least one property,preferably the at least one optical property, of the light beam which ismodified in a spatially resolved fashion by the spatial light modulator.Thus, preferably, the at least one property of the light beam modifiedby the spatial light modulator in a spatially resolved fashion is atleast one property selected from the group consisting of: an intensityof the portion of the light beam; a phase of the portion of the lightbeam; a spectral property of the portion of the light beam, preferably acolor; a polarization of the portion of the light beam; a direction ofpropagation of the portion of the light beam. As an example, as outlinedabove, the spatial light modulator, for each pixel, may be adapted toswitch on or off the portion of light passing the respective pixel, i.e.being adapted to switch between a first state in which the portion oflight may proceed towards the optical sensor and a second state in whichthe portion of light is prevented from proceeding towards the opticalsensor. Still, other options are feasible, such as an intensitymodulation between a first state having a first transmission of thepixel and a second state having a second transmission of the pixel beingdifferent from the first transmission. Other options are feasible.

The at least one spatial light modulator preferably may comprise atleast one spatial light modulator selected from the group consisting of:a spatial light modulator based on liquid crystal technology, such asone or more liquid crystal spatial light modulators; a spatial lightmodulator based on a micromechanical system, such as a spatial lightmodulator based on a micro-mirror system, specifically a micro-mirrorarray; a spatial light modulator based on interferometric modulation; aspatial light modulator based on an acousto-optical effect; a spatiallight modulator based on an electro-optical effect, specifically basedon the Pockels-effect and/or the Kerr-effect; a transmissive spatiallight modulator, wherein the light beam passes through the matrix ofpixels and wherein the pixels are adapted to modify the optical propertyfor each portion of the light beam passing through the respective pixelin an individually controllable fashion; a reflective spatial lightmodulator, wherein the pixels have individually controllable reflectiveproperties and are adapted to individually change a direction ofpropagation for each portion of the light beam being reflected by therespective pixel; a transmissive spatial light modulator, wherein thepixels have individually controllable reflective properties and areadapted to individually change a transmission for each pixel bycontrolling a position of a micro-mirror assigned to the respectivepixel; a spatial light modulator based on interferometric modulation,wherein the light beam passes through the matrix of pixels and whereinthe pixels are adapted to modify the optical property for each portionof the light beam passing through the respective pixel by modifyinginterferometric effects of the pixels; an electrochromic spatial lightmodulator, wherein the pixels have controllable spectral propertiesindividually controllable by an electric voltage applied to therespective pixel; an acousto-optical spatial light modulator, wherein abirefringence of the pixels is controllable by acoustic waves; anelectro-optical spatial light modulator, wherein a birefringence of thepixels is controllable by electric fields, preferably a spatial lightmodulator based on the Pockels effect and/or on the Kerr effect; aspatial light modulator comprising at least one array of tunable opticalelements, such as one or more of an array of focus-tunable lenses, anarea of adaptive liquid micro-lenses, an array of transparentmicro-prisms. These types of spatial light modulator generally are knownto the skilled person and, at least partially, are commerciallyavailable. Thus, as an example, the at least one spatial light modulatormay comprise at least one spatial light modulator selected from thegroup consisting of: a liquid crystal device, preferably an activematrix liquid crystal device, wherein the pixels are individuallycontrollable cells of the liquid crystal device; a micro-mirror device,wherein the pixels are micro-mirrors of the micro-mirror deviceindividually controllable with regard to an orientation of theirreflective surfaces; an electrochromic device, wherein the pixels arecells of the electrochromic device having spectral propertiesindividually controllable by an electric voltage applied to therespective cell; an acousto-optical device, wherein the pixels are cellsof the acousto-optical device having a birefringence individuallycontrollable by acoustic waves applied to the cells; an electro-opticaldevice, wherein the pixels are cells of the electro-optical devicehaving a birefringence individually controllable by electric fieldsapplied to the cells. Combinations of two or more of the namedtechnologies are feasible. Micro-mirror devices generally arecommercially available, such as micro-mirror devices implementing theso-called DLP® technology.

As outlined above, the capability of the pixels to modify the at leastone property of the light beam may be uniform over the matrix of pixels.Alternatively, the capability of the pixels to modify the at least oneproperty may differ between the pixels, such that at least one firstpixel of the matrix of pixels has a first capability of modifying theproperty, and at least one second pixel of the matrix of pixels has asecond capability of modifying the property. Further, more than oneproperty of the light beam may be modified by the pixels. Again, thepixels may be capable of modifying the same property of the light beamor different types of properties of the light beam. Thus, as an example,at least one first pixel may be adapted to modify a first property ofthe light beam, and at least one second pixel may be adapted to modify asecond property of the light beam being different from the firstproperty of the light beam. Further, the capability of the pixels tomodify the at least one optical property of the portion of the lightbeam passing the respective pixel may be dependent on the spectralproperties of the light beam, specifically of the color of the lightbeam. Thus, as an example, the capability of the pixels to modify the atleast one property of the light beam may be dependent on a wavelength ofthe light beam and/or of a color of a light beam, wherein the term“color” generally refers to the spectral distribution of the intensitiesof the light beam. Again, the pixels may have uniform properties ordiffering properties. Thus, as an example, at least one first pixel orat least one first group of pixels may have filtering properties with ahigh transmission in a blue spectral range, a second group of pixels mayhave filtering properties with a high transmission in a red spectralrange, and a third group of pixels may have filtering properties with ahigh transmission in a green spectral range. Generally, at least twogroups of pixels may be present having filtering properties for thelight beam with differing transmission ranges, wherein the pixels withineach group, additionally, may be switched between at least one lowtransmission state and at least one high transmission state. Otherembodiments are feasible.

As outlined above, the spatial light modulator may be a transparentspatial light modulator or an intransparent or opaque spatial lightmodulator. In the latter case, preferably, the spatial light modulatoris a reflective spatial light modulator such as a micro-mirror devicehaving a plurality of micro-mirrors, each micro-mirror forming a pixelof the micro-mirror device, wherein each micro-mirror is individuallyswitchable between at least two orientations. Thus, as an example, afirst orientation of each micro-mirror may be an orientation in whichthe portion of the light beam passing the micro-mirror, i.e. impingingon the micro-mirror, is directed towards the optical sensor, and asecond orientation may be an orientation in which the portion of thelight beam passing the micro-mirror, i.e. impinging on the micro-mirror,is directed towards another direction and does not reach the opticalsensor, e.g. by being directed into a beam dump.

Additionally or alternatively, the spatial light modulator may be atransmissive spatial light modulator, preferably a transmissive spatiallight modulator in which a transmissivity of the pixels is switchable,preferably individually. Thus, as an example, the spatial lightmodulator may comprise at least one transparent liquid crystal device,such as a liquid crystal device widely used for projecting purposes,e.g. in beamers used for presentation purposes. The liquid crystaldevice may be a monochrome liquid crystal device having pixels ofidentical spectral properties or may be a multi-chrome or evenfull-color liquid crystal device having pixels of differing spectralproperties, such as red green and blue pixels.

As outlined above, the evaluation device preferably is adapted to assigneach of the signal components to a pixel of the matrix. The evaluationdevice may further be adapted to determine which pixels of the matrixare illuminated by the light beam by evaluating the signal components.Thus, since each signal component may correspond to a specific pixel viaa unique correlation, an evaluation of the spectral components may leadto an evaluation of the illumination of the pixels. As an example, theevaluation device may be adapted to compare the signal components withat least one threshold in order to determine the illuminated pixels. Theat least one threshold may be a fixed threshold or predeterminedthreshold or may be a variable or adjustable threshold. As an example, apredetermined threshold above typical noise of the signal components maybe chosen, and, in case a signal component of a respective pixel exceedsthe threshold, an illumination of the pixel may be determined. The atleast one threshold may be a uniform threshold for all signal componentsor may be an individual threshold for the respective signal component.Thus, in case different signal components are prone to show differentdegrees of noise, an individual threshold may be chosen in order to takeaccount of these individual noises.

The evaluation device may further be adapted to identify at least onetransversal position of the light beam and/or an orientation of thelight beam, such as an orientation with regard to an optical axis of thedetector, by identifying a transversal position of pixels of the matrixilluminated by the light beam. Thus, as an example, a center of thelight beam on the matrix of pixels may be identified by identifying theat least one pixel having the highest illumination by evaluating thesignal components. The at least one pixel having the highestillumination may be located at a specific position of the matrix whichagain may then be identified as the transversal position of the lightbeam. In this regard, generally, reference may be made to the principleof determining a transversal position of the light beam as disclosed inEuropean patent application number EP 13171901.5, even though otheroptions are feasible.

Generally, as will be used in the following, several directions of thedetector may be defined. Thus, a position and/or orientation of anobject may be defined in a coordinate system, which, preferably, may bea coordinate system of the detector. Thus, the detector may constitute acoordinate system in which an optical axis of the detector forms thez-axis and in which, additionally, an x-axis and a y-axis may beprovided which are perpendicular to the z-axis and which areperpendicular to each other. As an example, the detector and/or a partof the detector may rest at a specific point in this coordinate system,such as at the origin of this coordinate system. In this coordinatesystem, a direction parallel or antiparallel to the z-axis may beregarded as a longitudinal direction, and a coordinate along the z-axismay be considered a longitudinal coordinate. An arbitrary directionperpendicular to the longitudinal direction may be considered atransversal direction, and an x- and/or y-coordinate may be considered atransversal coordinate.

Alternatively, other types of coordinate systems may be used. Thus, asan example, a polar coordinate system may be used in which the opticalaxis forms a z-axis and in which a distance from the z-axis and a polarangle may be used as additional coordinates. Again, a direction parallelor antiparallel to the z-axis may be considered a longitudinaldirection, and a coordinate along the z-axis may be considered alongitudinal coordinate. Any direction perpendicular to the z-axis maybe considered a transversal direction, and the polar coordinate and/orthe polar angle may be considered a transversal coordinate.

The center of the Light beam on the matrix of, pixels, which may be acentral spot or a central area of the light beam on the matrix ofpixels, may be used in various ways. Thus, at least one transversalcoordinate for the center of the light beam may be determined, which, inthe following, will also be referred to as the xy-coordinate of thecenter of the light beam.

Further, the position of the center of the light beam may allow forobtaining information regarding a transversal position and/or a relativedirection of an object from which the light beam propagates towards thedetector. Thus, the transversal position of the pixels of the matrixilluminated by the light beam is determined by determining one or morepixels having the highest illumination by the light beam. For thispurpose, known imaging properties of the detector may be used. As anexample, a light beam propagating from the object with the detector maydirectly impinge on a specific area, and from the location of this areaor specifically from the position of the center of the light beam, atransversal position and/or a direction of the object may be derived.Optionally, the detector may comprise at least one transfer device, suchas at least one lens or lens system, having optical properties. Since,typically, the optical properties of the transfer device are known, suchas by using known imaging equations and/or geometric relationships knownfrom ray optics or matrix optics, the position of the center of thelight beam on the matrix of pixels may also be used for derivinginformation on a transversal position of the object in case one or moretransfer devices are used. Thus, generally, the evaluation device may beadapted to identify one or more of a transversal position of an objectfrom which the light beam propagates towards the detector and a relativedirection of the object from which the light beam propagates towards thedetector, by evaluating at least one of the transversal position of thelight beam and the orientation of the light beam. In this regard, as anexample, reference may also be made to one or more of the transversaloptical sensors as disclosed in one or more of European patentapplication number EP 13171901.5, U.S. provisional application No.61/739,173 or U.S. provisional application No. 61/749,964. Still, otheroptions are feasible.

The evaluation device may further be adapted to derive one or more otheritems of information relating to the light beam and/or relating to aposition of an object from which the light beam propagates towards thedetector by further evaluating the results of the spectral analysis,specifically by evaluating the signal components. Thus, as an example,the evaluating device may be adapted to derive one or more items ofinformation selected from the group consisting of: a position of anobject from which the light beam propagates towards the detector; atransversal position of the light beam on the matrix of pixels of thespatial light modulator; a width of the light beam at the position ofthe matrix of the pixels of the spatial light modulator; a color of thelight beam and/or spectral properties of the light beam; a longitudinalcoordinate of the object from which the light beam propagates towardsthe detector. Examples of these items of information and deriving theseitems of information will be given in further detail below.

Thus, as an example, the evaluation device may be adapted to determine awidth of the light beam by evaluating the signal components. Generally,as used herein, the term “width of the light beam” refers to anarbitrary measure of a transversal extension of a spot of illuminationgenerated by the light beam on the matrix of pixels, specifically in aplane perpendicular to a local direction of propagation of the lightbeam, such as the above-mentioned z-axis. Thus, as an example, the widthof the light beam may be specified by providing one or more of an areaof the light spot, a diameter of the light spot, an equivalent diameterof the light spot, a radius of the light spot or an equivalent radius ofthe light spot. As an example, the so-called beam waist may be specifiedin order to determine the width of the light beam at the position of thespatial light modulator, as will be outlined in further detail below.Specifically, the evaluation device may be adapted to identify thesignal components assigned to pixels being illuminated by the light beamand to determine the width of the light beam at the position of thespatial light modulator from known geometric properties of thearrangement of the pixels. Thus, specifically, in case the pixels of thematrix are located at known positions of the matrix, which typically isthe case, the signal components of the respective pixels as derived bythe frequency analysis may be transformed into a spatial distribution ofillumination of the spatial light modulator by the light beam, therebybeing able to derive at least one item of information regarding thewidth of the light beam at the position of the spatial light modulator.

In case the width of the light beam is known, the width may be used forderiving one or more items of information regarding the position of theobject from which the light beam travels towards the detector. Thus, theevaluation device, using a known or determinable relationship betweenthe width of the light beam and the distance between an object fromwhich the light beam propagates towards the detector, may be adapted todetermine a longitudinal coordinate of the object. For the generalprinciple of deriving a longitudinal of an object by evaluating a widthof a light beam, reference may be made to one or more of WO 2012/110924A1, EP 13171901.5, U.S. provisional application No. 61/739,173 or U.S.provisional application No. 61/749,964.

Thus, as an example, the evaluation device may be adapted to compare,for each of the pixels, the signal component of the respective pixel toat least one threshold in order to determine whether the pixel is anilluminated pixel or not. This at least one threshold may be anindividual threshold for each of the pixels or may be a threshold whichis a uniform threshold for the whole matrix. As will be outlined above,the threshold may be predetermined and/or fixed.

Alternatively, the at least one threshold may be variable. Thus, the atleast one threshold may be determined individually for each measurementor groups of measurements. Thus, at least one algorithm may be providedadapted to determine the threshold.

The evaluation device generally may be adapted to determine at least onepixel having the highest illumination out of the pixels by comparing thesignals of the pixels. Thus, the detector generally may be adapted todetermine one or more pixels and/or an area or region of the matrixhaving the highest intensity of the illumination by the light beam. Asan example, in this way, a center of illumination by the light beam maybe determined.

The highest illumination and/or the information about the at least onearea or region of highest illumination may be used in various ways.Thus, as outlined above, the at least one above-mentioned threshold maybe a variable threshold. As an example, the evaluation device may beadapted to choose the above-mentioned at least one threshold as afraction of the signal of the at least one pixel having the highestillumination, Thus, the evaluation device may be adapted to choose thethreshold by multiplying the signal of the at least one pixel having thehighest illumination with a factor of 1/e². As will be outlined infurther detail below, this option is particularly preferred in caseGaussian propagation properties are assumed for the at least one lightbeam, since the threshold 1/e² generally determines the borders of alight spot having a beam radius or beam waist w generated by a Gaussianlight beam on the optical sensor.

The evaluation device may be adapted to determine the longitudinalcoordinate of the object by using a predetermined relationship betweenthe width of the light beam or, which is equivalent, the number N of thepixels which are illuminated by the light beam, and the longitudinalcoordinate of the object. Thus, generally, the diameter of the lightbeam, due to propagation properties generally known to the skilledperson, changes with propagation, such as with a longitudinal coordinateof the propagation. The relationship between the number of illuminatedpixels and the longitudinal coordinate of the object may be anempirically determined relationship and/or may be analyticallydetermined.

Thus, as an example, a calibration process may be used for determiningthe relationship between the width of the light beam and/or the numberof illuminated pixels and the longitudinal coordinate. Additionally oralternatively, as mentioned above, the predetermined relationship may bebased on the assumption of the light beam being a Gaussian light beam.The light beam may be a monochromatic light beam having a precisely onewavelength λ or may be a light beam having a plurality of wavelengths ora wavelength spectrum, wherein, as an example, a central wavelength ofthe spectrum and/or a wavelength of a characteristic peak of thespectrum may be chosen as the wavelength λ of the light beam.

As an example of an analytically determined relationship, thepredetermined relationship, which may be derived by assuming Gaussianproperties of the light beam, may be:

$\begin{matrix}{{N\text{∼}{\pi \cdot w_{0}^{2} \cdot \left( {1 + \left( \frac{z}{z_{0}} \right)^{2}} \right)}},} & (1)\end{matrix}$wherein z is the longitudinal coordinate,wherein w₀ is a minimum beam radius of the light beam when propagatingin space,wherein z₀ is a Rayleigh-length of the light beam with z₀=π·w₀ ^(z)/λ, λbeing the wavelength of the light beam.

This relationship may generally be derived from the general equation ofan intensity I of a Gaussian light beam traveling along a z-axis of acoordinate system, with r being a coordinate perpendicular to the z-axisand E being the electric field of the light beam:I(r,z)=|E(r,z)|² =l ₀·(w ₀ /w(z))² ·e ^(−2r) ² /w(z)²  (2)

The beam radius w of the transversal profile of the Gaussian light beamgenerally representing a Gaussian curve is defined, for a specificz-value, as a specific distance from the z-axis at which the amplitude Ehas dropped to a value of 1/e (approx. 36%) and at which the intensity Ihas dropped to 1/e². The minimum beam radius, which, in the Gaussianequation given above (which may also occur at other z-values, such aswhen performing a z-coordinate transformation), occurs at coordinatez=0, is denoted by w₀. Depending on the z-coordinate, the beam radiusgenerally follows the following equation when light beam propagatesalong the z-axis:

$\begin{matrix}{{w(z)} = {w_{0} \cdot \sqrt{1 + \left( \frac{z}{z_{0}} \right)^{2}}}} & (3)\end{matrix}$

With the number N of illuminated pixels being proportional to theilluminated area A of the optical sensor:N˜A  (4)or, in case a plurality of spatial light modulators i=1, . . . , n isused, with the number N_(i) of illuminated pixels for each spatial lightmodulator being proportional to the illuminated area A_(i) of therespective optical sensorN _(i) ˜A _(i)  (4′)and the general area of a circle having a radius w:A=π·w ²,  (5)the following relationship between the number of illuminated pixels andthe z-coordinate may be derived:

$\begin{matrix}{N\text{∼}{\pi \cdot w_{0}^{2} \cdot \left( {1 + \left( \frac{z}{z_{0}} \right)^{2}} \right)}} & (6) \\{or} & \; \\{{N_{i}\text{∼}{\pi \cdot w_{0}^{2} \cdot \left( {1 + \left( \frac{z}{z_{0}} \right)^{2}} \right)}},} & \left( 6^{\prime} \right)\end{matrix}$respectively, with z₀=π·w₀ ²/λ, as mentioned above. Thus, with N orN_(i), respectively, being the number of pixels within a circle beingilluminated at an intensity o I≥I₀/e², as an example, N or N_(i) may bedetermined by simple counting of pixels and/or other methods, such as ahistogram analysis. In other words, a well-defined relationship betweenthe z-coordinate and the number of illuminated pixels N or N_(i),respectively, may be used for determining the longitudinal coordinate zof the object and/or of at least one point of the object, such as atleast one longitudinal coordinate of at least one beacon device beingone of integrated into the object and/or attached to the object.

In the equations given above, such as in equation (1), it is assumedthat the light beam has a focus at position z=0. It shall be noted,however, that a coordinate transformation of the z-coordinate ispossible, such as by adding and/or subtracting a specific value. Thus,as an example, the position of the focus typically is dependent on thedistance of the object from the detector and/or on other properties ofthe light beam. Thus, by determining the focus and/or the position ofthe focus, a position of the object, specifically a longitudinalcoordinate of the object, may be determined, such as by using anempirical and/or an analytical relationship between a position of thefocus and a longitudinal coordinate of the object and/or the beacondevice. Further, imaging properties of the at least one optionaltransfer device, such as the at least one optional lens, may be takeninto account. Thus, as an example, in case beam properties of the lightbeam being directed from the object towards the detector are known, suchas in case emission properties of an illuminating device contained in abeacon device are known, by using appropriate Gaussian transfer matricesrepresenting a propagation from the object to the transfer device,representing imaging of the transfer device and representing beampropagation from the transfer device to the at least one optical sensor,a correlation between a beam waist and a position of the object and/orthe beacon device may easily be determined analytically. Additionally oralternatively, a correlation may empirically be determined byappropriate calibration measurements.

As outlined above, the matrix of pixels preferably may be atwo-dimensional matrix. However, other embodiments are feasible, such asone-dimensional matrices. More preferably, as outlined above, the matrixof pixels is a rectangular matrix.

As outlined above, the information derived by the frequency analysis mayfurther be used to derive other types of information regarding theobject and/or the light beam. As a further example of information whichmay be derived additionally or alternatively to transversal and/orlongitudinal position information, color and/or spectral properties ofthe object and/or the light beam may be named.

Thus, the capability of the pixels to modify the at least one opticalproperty of the portion of the light beam passing the respective pixelmay be dependent on the spectral properties of the light beam,specifically of the color of the light beam. The evaluation devicespecifically may be adapted to assign the signal components tocomponents of the light beam having differing spectral properties. Thus,as an example, one or more first signal components may be assigned toone or more pixels adapted to transmit or reflect portions of the lightbeam in a first spectral range, one or more second signal components maybe assigned to one or more pixels adapted to transmit or reflectportions of the light beam in a second spectral range, and one or morethird signal components may be assigned to one or more pixels adapted totransmit or reflect portions of the light beam in a third spectralrange. Thus, the matrix of pixels may have at least two different groupsof pixels having different spectral properties, and the evaluationdevice may be adapted to distinguish between signal components of thesegroups, thereby allowing for a full or partial spectral analysis of thelight beam. As an example, the matrix may have red, green and bluepixels, which each may be controlled individually, and the evaluationdevice may be adapted to assign signal components to one of the groups.For example, a full-color liquid crystal SLM may be used for thispurpose.

Thus, generally, the evaluation device may be adapted to determine acolor of the light beam by comparing signal components being assigned tocomponents of the light beam having differing spectral properties,specifically being assigned to components of the light beam havingdiffering wavelengths. The matrix of pixels may comprise pixels havingdiffering spectral properties, preferably having differing color,wherein the evaluation device may be adapted to assign signal componentsto the respective pixels having differing spectral properties. Themodulator device may be adapted to control pixels having a first colorin a different way than pixels having a second color.

As outlined above, one of the advantages of the present inventionresides in the fact that a fine pixelation of the optical sensor may beavoided. Instead, the pixelated SLM may be used, thereby, in fact,transferring the pixelation from the actual optical sensor to the SLM.Specifically, the at least one optical sensor may be or may comprise atleast one large-area optical sensor being adapted to detect a pluralityof portions of the light beam passing through a plurality of the pixels.Thus, the at least one optical sensor may provide a single,non-segmented unitary sensor region adapted to provide a unitary sensorsignal, wherein the sensor region is adapted to detect all portions ofthe light beam passing the SLM, at least for light beams entering thedetector and passing one or both of the SLM or the optical sensorparallel to the optical axis. As an example, the unitary sensor regionmay have a sensitive area of at least 25 mm², preferably of at least 100mm² and more preferably of at least 400 mm². Still, other embodimentsare feasible, such as embodiments having two or more sensor regions.Further, in case two or more optical sensors are used, the opticalsensors do not necessarily have to be identical. Thus, one or morelarge-area optical sensors may be combined with one or more pixelatedoptical sensors, such as with one or more camera chips, e.g. one or moreCCD- or CMOS-chips, as will be outlined in further detail below.

The at least one optical sensor or, in case a plurality of opticalsensors is provided, at least one of the optical sensors preferably maybe fully or partially transparent. Thus, generally, the at least oneoptical sensor may comprise at least one at least partially transparentoptical sensor such that the light beam at least partially may passthrough the parent optical sensor. As used herein, the term “at leastpartially transparent” may both refer to the option that the entireoptical sensor is transparent or a part (such as a sensitive region) ofthe optical sensor is transparent and/or to the option that the opticalsensor or at least a transparent part of the optical sensor may transmitthe light beam in an attenuated or non-attenuated fashion. Thus, as anexample, the transparent optical sensor may have a transparency of atleast 10%, preferably at least 20%, at least 40%, at least 50% or atleast 70%. The transparency may depend on the wavelength of the lightbeam, and the given transparencies may be valid for at least onewavelength in at least one of the infra-red spectral range, the visiblespectral range and the ultraviolet spectral range. Generally, as usedherein, the infrared spectral range refers to a range of 780 nm to 1 mm,preferably to a range of 780 nm to 50 μm, more preferably to a range of780 nm to 3.0 μm. The visible spectral range refers to a range of 380 nmto 780 nm. Therein, the blue spectral range, including the violetspectral range, may be defined as 380 nm to 490 nm, wherein the pureblue spectral range may be defined as 430 to 490 nm. The green spectralrange, including the yellow spectral range, may be defined as 490 nm to600 nm, wherein the pure green spectral range may be defined as 490 nmto 470 nm. The red spectral range, including the orange spectral range,may be defined as 600 nm to 780 nm, wherein the pure red spectral rangemay be defined as 640 to 780 nm. The ultraviolet spectral range may bedefined as 1 nm to 380 nm, preferably 50 nm to 380 nm, more preferably200 nm to 380 nm.

In order to provide a sensory effect, generally, the optical sensortypically has to provide some sort of interaction between the light beamand the optical sensor which typically results in a loss oftransparency. The transparency of the optical sensor may be dependent ona wavelength of the light beam, resulting in a spectral profile of asensitivity, an absorption or a transparency of the optical sensor. Asoutlined above, in case a plurality of optical sensors is provided, thespectral properties of the optical sensors do not necessarily have to beidentical. Thus, one of the optical sensors may provide a strongabsorption (such as one or more of an absorbance peak, an absorptivitypeak or an absorption peak) in the red spectral region, another one ofthe optical sensors may provide a strong absorption in the greenspectral region, and another one may provide a strong absorption in theblue spectral region. Other embodiments are feasible.

As outlined above, in case a plurality of optical sensors is provided,the optical sensors may form a stack. Thus, the at least one opticalsensor comprises a stack of at least two optical sensors. At least oneof the optical sensors of the stack may be an at least partiallytransparent optical sensor. Thus, preferably, the stack of opticalsensors may comprise at least one at least partially transparent opticalsensor and at least one further optical sensor which may be transparentor intransparent. Preferably, at least two transparent optical sensorsare provided. Specifically, an optical sensor on a side furthest awayfrom the spatial light modulator may also be an intransparent opticalsensor, such as an opaque sensor, wherein organic or inorganic opticalsensors may be used, such as inorganic semiconductor sensors like CCD orCMOS chips.

The stack may be partially or fully immersed in an oil and/or liquid toavoid and/or decrease reflections at interfaces. Thus, at least one ofthe optical sensors of the stack may fully or partially be immersed inthe oil and/or the liquid.

As outlined above, the at least one optical sensor necessarily has to bea pixelated optical sensor. Thus, by using the general idea ofperforming the frequency analysis, a pixelation may be omitted. Still,specifically in case a plurality of optical sensors is provided, one ormore pixelated optical sensors may be used. Thus, specifically in case astack of optical sensors is used, at least one of the optical sensors ofthe stack may be a pixelated optical sensor having a plurality oflight-sensitive pixels. As an example, the pixelated optical sensor maybe a pixelated organic and/or inorganic optical sensor. Most preferably,specifically due to their commercial availability, the pixelated opticalsensor may be an inorganic pixelated optical sensor, preferably a CCDchip or a CMOS chip. Thus, as an example, the stack may comprise one ormore transparent large-area non-pixelated optical sensors, such as oneor more DSCs and more preferably sDSCs (as will be outlined in furtherdetail below), and at least one inorganic pixelated optical sensor, suchas a CCD chip or a CMOS chip. As an example, the at least one inorganicpixelated optical sensor may be located on a side of the stack furthestaway from the spatial light modulator. Specifically, the pixelatedoptical sensor may be a camera chip and, more preferably, a full-colorcamera chip. Generally, the pixelated optical sensor may becolor-sensitive, i.e. may be a pixelated optical sensor adapted todistinguish between color components of the light beam, such as byproviding at least two different types of pixels, more preferably atleast three different types of pixels, having a different colorsensitivity. Thus, as an example, the pixelated optical sensor may be afull-color imaging sensor.

Preferably, the at least one optical sensor contains at least onelongitudinal optical sensor, i.e. an optical sensor which is adapted todetermine a longitudinal position of at least one object, such as atleast one z-coordinate of an object. Preferably, the optical sensor or,in case a plurality of optical sensors is provided, at least one of theoptical sensors may have a setup and/or may provide the functions of theoptical sensor as disclosed in WO 2012/110924 A1. Thus, preferably, theat least one optical sensor and/or one or more of the optical sensorsmay have at least one sensor region, wherein the sensor signal of theoptical sensor is dependent on an illumination of the sensor region bythe light beam, wherein the sensor signal, given the same total power ofthe illumination, is dependent on a geometry, specifically a width, ofthe light beam in the sensor region, wherein the evaluation device isadapted to determine the width by evaluating the sensor signal. In thefollowing, this effect generally will be referred to as the FiP-effect,since, given the same total power p of illumination, the sensor signal iis dependent on a flux F of photons, i.e. the number of photons per unitarea. It shall be noted, however, that a detector based on theFiP-effect is simply a preferred embodiment of a longitudinal opticalsensor. Additionally or alternatively, one or more other types oflongitudinal optical sensors may be used. Thus, in the following, incase reference is made to a FiP sensor, it shall be noted that,generally, other types of longitudinal optical sensors may be usedinstead. Still, due to the superior properties and due to the advantagesof FiP sensors, the use of at least one FiP sensor is preferred.

The FiP-effect, which is further disclosed in U.S. provisionalapplications 61/739,173 and 61/749,964, may be used for determining alongitudinal position of an object from which the light beam travelstowards the detector. Thus, since the beam with the light beam on thesensor region, which preferably may be a non-pixelated sensor region,depends on a width, such as a diameter or radius, of the light beamwhich again depends on a distance between the detector and the object,the sensor signal may be used for determining a longitudinal coordinateof the object. Thus, as an example, the evaluation device may be adaptedto use a predetermined relationship between a longitudinal coordinate ofthe object and a sensor signal in order to determine the longitudinalcoordinate. The predetermined relationship may be derived by usingempiric calibration measurements and/or by using known beam propagationproperties, such as Gaussian beam propagation properties. For furtherdetails, reference may be made to WO 2012/110924 A1 and/or U.S.provisional applications 61/739,173 and 61/749,964.

Preferably, in case a plurality of optical sensors is provided, such asa stack of optical sensors, at least two of the optical sensors may beadapted to provide the FiP-effect. Specifically, one or more opticalsensors may be provided which exhibit the FiP-effect, wherein,preferably, the optical sensors exhibiting the FiP-effect are large-areaoptical sensors having a uniform sensor surface rather than beingpixelated optical sensors.

Thus, by evaluating signals from optical sensors which subsequently areilluminated by the light beam, such as subsequent optical sensors of asensor stack, and by using the above-mentioned FiP-effect, ambiguitiesin a beam profile may be resolved. Thus, Gaussian light beams mayprovide the same beam width at a distance z before and after a focalpoint. By measuring the beam width along at least two positions, thisambiguity may be resolved, by determining whether the light beam stillis narrowing or widening. Thus, by providing two or more optical sensorshaving the FiP-effect, a higher accuracy may be provided. The evaluationdevice may be adapted to determine the widths of the light beam in thesensor regions of the at least two optical sensors, and the evaluationdevice may further be adapted to generate at least one item ofinformation on a longitudinal position of an object from which the lightbeam propagates towards the optical detector, by evaluating the widths.

Specifically in case the at least one optical sensor or one or more ofthe optical sensors provide the above-mentioned FiP-effect, the sensorsignal of the optical sensor may be dependent on a modulation frequencyof the light beam. As an example, the FiP-effect may function asmodulation frequencies of 0.1 Hz to 10 kHz.

Thus, generally, the light beam may be modulated by one or moremodulation devices. The modulation for enhancing and/or enabling theFiP-effect may be the same modulation as used by the modulator devicecontrolling the pixels of the spatial light modulator and/or may be adifferent modulation. Thus, the spatial light modulator may provide themodulation enabling and/or enhancing the FiP-effect. Additionally oralternatively, an additional modulation may be provided, such as byusing one or more illumination sources being adapted to emit the lightbeam in a modulated way. Thus, as an example, the modulation used by themodulator device and the pixels of the spatial light modulator may be ina first frequency range, such as in a range of 1 Hz to 100 Hz, whereas,additionally, the light beam itself may optionally additionally bemodulated by a at least one second modulation frequency, such as afrequency in a second frequency range of 100 Hz to 10 kHz. Furtherexamples of the first frequency range may be 100 to 500 Hz or 100 to1000 Hz. Further examples of the second frequency range may be 500 Hz to10 kHz or 1000 Hz to 10 kHz. Filtering below 100 Hz may be advantageousto remove noise from light sources such as fluorescent lamps. Thus, forexample, more than one modulation may be used, wherein at least onefirst modulation generated by the spatial light modulator and themodulator device may be used for assigning a signal component to one ormore specific pixels of the spatial light modulator and wherein at leastone further modulation may be used for one or more different purposes,such as for enhancing and/or enabling the FiP-effect and/or foridentifying one or more illumination sources emitting at a specificmodulation frequency. The latter purpose may be used for distinguishingbetween two or more different types of beacon devices emitting modulatedlight beams at different modulation frequencies. For further details,reference may be made to EP 13171900.7, filed on Jun. 13, 2013.

As outlined above, the at least one optical sensor or, in case aplurality of optical sensors is provided, one or more of the opticalsensors preferably may be or may comprise at least one organicsemiconductor detector and/or at least one inorganic semiconductordetector. Thus, generally, the optical detector may comprise at leastone semiconductor detector. Most preferably, the semiconductor detectoror at least one of the semiconductor detectors may be an organicsemiconductor detector comprising at least one organic material. Thus,as used herein, an organic semiconductor detector is an optical detectorcomprising at least one organic material, such as an organic dye and/oran organic semiconductor material. Besides the at least one organicmaterial, one or more further materials may be comprised, which may beselected from organic materials or inorganic materials. Thus, theorganic semiconductor detector may be designed as an all-organicsemiconductor detector comprising organic materials only, or as a hybriddetector comprising one or more organic materials and one or moreinorganic materials. Still, other embodiments are feasible. Thus,combinations of one or more organic semiconductor detectors and/or oneor more inorganic semiconductor detectors are feasible. Preferably, thesemiconductor detector may be selected from the group consisting of anorganic solar cell, a dye solar cell, a dye-sensitized solar cell, asolid dye solar cell, a solid dye-sensitized solar cell.

Preferably, specifically in case one or more of the optical sensorsprovide the above-mentioned FiP-effect, the at least one optical sensoror, in case a plurality of optical sensors is provided, one or more ofthe optical sensors, may be or may comprise a dye-sensitized solar cell(DSC), preferably a solid dye-sensitized solar cell (sDSC). As usedherein, a DSC generally refers to a setup having at least twoelectrodes, wherein at least one of the electrodes is at least partiallytransparent, wherein at least one n-semiconducting metal oxide, at leastone dye and at least one electrolyte or p-semiconducting material isembedded in between the electrodes. In an sDSC, the electrolyte orp-semiconducting material is a solid material. Generally, for potentialsetups of sDSCs which may also be used for one or more of the opticalsensors within the present invention, reference may be made to one ormore of WO 2012/110924 A1, U.S. provisional applications 61/739,173 and61/749,964, EP 13171898.3, EP 13171900.7 or EP 13171901.5. Otherembodiments are feasible. The above-mentioned FiP-effect, asdemonstrated in WO 2012/110924 A1, specifically may be present in sDSCs.

Thus, generally, the at least one optical sensor may comprise at leastone optical sensor having a layer setup comprising at least one firstelectrode, at least one n-semiconducting metal oxide, at least one dye,at least one p-semiconducting organic material, preferably a solidp-semiconducting organic material, and at least one second electrode. Asoutlined above, at least one of the first electrode and the secondelectrode may be transparent. Most preferably, specifically in case atransparent optical sensor shall be provided, both the first electrodeand the second electrode may be transparent.

As outlined above, the optical detector may contain one or more furtherdevices, specifically one or more further optical devices such as one ormore lenses and/or one or more reflecting devices. Thus, mostpreferably, the optical detector may comprise a setup, such as a setuparranged in a tubular fashion, the setup having the at least one spatiallight modulator and at least one optical sensor, preferably a stack ofat least two optical sensors, located behind the spatial light modulatorsuch that a light beam having passed the spatial light modulatorsubsequently passes the one or more optical sensors. Preferably beforepassing the spatial light modulator, the light beam may pass one or moreoptical devices such as one or more lenses, preferably one or moreoptical devices adapted for influencing a beam shape and/or a beamwidening or narrowing in a well-defined fashion. Additionally oralternatively, one or more optical devices such as one or more lensesmay be placed in between the spatial light modulator and the at leastone optical sensor.

The one or more optical devices generally may be referred to as atransfer device, since one of the purposes of the transfer device mayreside in a well-defined transfer of the light beam into the opticaldetector. As used herein, consequently, the term “transfer device”generally refers to an arbitrary device or combination of devicesadapted for guiding and/or feeding the light beam onto one or more ofthe spatial light modulator or the optical sensor, preferably byinfluencing one or more of a beam shape, a beam width or a wideningangle of the light beam in a well-defined fashion, such as a lens or acurved mirror do.

Thus, generally, the optical detector may further comprise at least onetransfer device adapted for feeding light into the optical detector. Thetransfer device may be adapted to focus and/or collimate light onto oneor more of the spatial light modulator and the optical sensor. Thetransfer device specifically may comprise one or more devices selectedfrom the group consisting of: a lens, a focusing mirror, a defocusingmirror, a reflector, a prism, an optical filter, a diaphragm. Otherembodiments are feasible.

A further aspect of the present invention may refer to the option ofimage recognition, pattern recognition and individually determiningz-coordinates of different regions of an image captured by the opticaldetector. Thus, generally, as outlined above, the optical detector maybe adapted to capture at least one image, such as a 2D-image. For thispurpose, as outlined above, the optical detector may comprise at leastone imaging device such as at least one pixelated optical sensor. As anexample, the at least one pixelated optical sensor may comprise at leastone CCD sensor and/or at least one CMOS sensor. By using this at leastone imaging device, the optical detector may be adapted to capture atleast one regular two-dimensional image of a scene and/or at least oneobject. The at least one image may be or may comprise at least onemonochrome image and/or at least one multi-chrome image and/or at leastone full-color image. Further, the at least one image may be or maycomprise a single image or may comprise a series of images.

Further, as outlined above, the optical detector may comprise at leastone distance sensor adapted for determining a distance of at least oneobject from the optical detector, also referred to as a z-coordinate.Thus, specifically, the so-called FiP-effect may be used, as outlinedabove and as disclosed e.g. in WO 2012/110924 A1 and/or in one or moreof U.S. provisional applications 61/739,173 and 61/749,964. Thus, the atleast one optical sensor or, in case a plurality of optical sensors iscomprised, at least one of the optical sensors, may be embodied as aso-called FiP-sensor, i.e. a sensor having at least one sensor region,wherein the sensor signal of the FiP-sensor is dependent on anillumination of the sensor region by the light beam, wherein the sensorsignal, given the same total power of the illumination, is dependent ona width of the light beam in the sensor region. Thus, generally, inFiP-sensors, a known relationship between the sensor signal and az-coordinate of an object from which the light beam travels towards theoptical detector may be used for determining the z-coordinate of theobject and/or a part thereof. The optical detector generally maycomprise one or more FiP-sensors, preferably a stack of FiP-sensors.

By using a combination of regular 2D-image capturing and the possibilityof determining z-coordinates, 3D-imaging is feasible.

In order to individually evaluate one or more objects and/or componentscontained within a scene captured within the at least one image, the atleast one image may be subdivided into two or more regions, wherein thetwo or more regions or at least one of the two or more regions may beevaluated individually. For this purpose, a frequency selectiveseparation of the signals corresponding to the at least two regions maybe performed.

Thus, the optical detector generally may be adapted to capture at leastone image, preferably a 2D-image. Further, the optical detector,preferably the at least one evaluation device, may be adapted to defineat least two regions in the image and to assign correspondingsuperpixels of the matrix of pixels of the spatial light modulator to atleast one of the regions, preferably to each of the regions. As usedherein, a region generally may be an area of the image or group ofpixels of an imaging device capturing the image corresponding to thearea, wherein, within the area, an identical or similar intensity orcolor may be present. Thus, generally, a region may be an image of atleast one object, the image of the at least one object forming a partialimage of the image captured by the optical detector. Thus, the opticaldetector may acquire an image of a scene, wherein, within the scene, atleast one object is present, wherein the object is imaged onto a partialimage.

Thus, within the image, at least two regions may be identified, such asby using an appropriate algorithm as will be outlined in further detailbelow. Since, generally, the imaging properties of the optical detectorare known, such as by using known imaging equations and/or matrixoptics, the regions of the image may be assigned to corresponding pixelsof the spatial light modulator. Thus, components of the at least onelight beam passing specific pixels of the matrix of pixels of thespatial light modulator subsequently may hit corresponding pixels of theimaging device. Thus, by subdividing the image into two or more regions,the matrix of pixels of the spatial light modulator may be subdividedinto two or more superpixels, each superpixel corresponding to arespective region of the image.

As outlined above, one or more image recognition algorithms may be usedfor determining the at least two regions. Thus, generally, the opticaldetector, preferably the at least one evaluation device, may be adaptedto define the at least two regions in the image by using at least oneimage recognition algorithm. Means and algorithms for image recognitiongenerally are known to the skilled person. Thus, as an example, the atleast one image recognition algorithm may be adapted to define the atleast two regions by recognizing boundaries of at least one of:contrast, color or intensity. As used herein, a boundary generally is aline along which a significant change in at least one parameter occurswhen crossing the line. Thus, as an example, gradients of one or moreparameters may be determined and, as an example, may be compared to oneor more threshold values. Specifically, the at least one imagerecognition algorithm may be selected from the group consisting of:Felzenszwalb's efficient graph based segmentation; Quickshift imagesegmentation; SLIC K-Means based image segmentation; Energy-Drivensampling; an edge detection algorithm such as a Canny algorithm; aMean-shift algorithm, such as a Cam shift algorithm (Cam: ContinuouslyAdaptive Mean shift); a Contour extraction algorithm. Additionally oralternatively, other algorithms may be used, such as one or more of:algorithms for edge, ridge, corner, blob, or feature detection;algorithms for dimensionality reduction; algorithms for textureclassification; algorithms for texture segmentation. These algorithmsare generally known to the skilled person. In the context of the presentinvention, these algorithms may be referred to as an image recognitionalgorithm, and image partitioning algorithm or a superpixel algorithm.As outlined above, the at least one image recognition algorithm isadapted to recognize one or more objects in the image. Thereby, as anexample, one or more objects of interest and/or one or more regions ofinterest may be determined, for further analysis, such as fordetermination of corresponding z-coordinates.

As outlined above, the superpixels may be chosen such that thesuperpixels and their corresponding regions are illuminated by the samecomponents of the light beam. Thus, the optical detector, preferably theat least one evaluation device, may be adapted to assign the superpixelsof the matrix of pixels of the spatial light modulator to at least oneof the regions, preferably to each of the regions such that eachcomponent of the light beam passing a specific pixel of the matrix ofpixels, the specific pixel belonging to a specific superpixel,subsequently hits the specific region of the at least two regions, thespecific region corresponding to the specific superpixel.

As indicated above, the assignment of superpixels may be used forsimplifying the modulation. Thus, by assigning superpixels tocorresponding regions of the image, the number of modulation frequenciesmay be reduced, thereby allowing for using a lower number of modulationfrequencies as compared to a process in which individual modulationfrequencies are used for each of the pixels. Thus, as an example, theoptical detector, preferably the at least one evaluation device, may beadapted to assign at least one first modulation frequency to at least afirst superpixel of the superpixels and at least one second modulationfrequency to at least a second superpixel of the superpixels, whereinthe first modulation frequency is different from the second modulationfrequency, and wherein the at least one modulator device is adapted forperiodically controlling the pixels of the first superpixel with the atleast one first modulation frequency and for periodically controllingthe pixels of the second superpixel with the at least one secondmodulation frequency. Thereby, the pixels of a specific superpixel maybe modulated by using a uniform modulation frequency assigned to thespecific superpixel. Further, optionally, the superpixel may besubdivided into sub-pixels and/or additionally modulations may beapplied within the superpixel. Using a uniform modulation frequency e.g.for a superpixel corresponding to an identified object within the imagegreatly simplifies the evaluation, since, as an example, a determinationof a z-coordinate of the object may be performed by evaluating the atleast one sensor signal (such as at least one sensor signal of at leastone FiP-sensor or a stack of FiP-sensors of the optical detector) in afrequency-selective way, by selectively evaluating the sensor signalshaving the respective modulation frequency assigned to the superpixel ofthe object. Thereby, within a scene captured by the optical detector,the object may be identified within the image, at least one superpixelmay be assigned to the object, and, by using at least one optical sensoradapted for determining a z-coordinate and by evaluating the at leastone sensor signal of said optical sensor in a frequency-selective way,the z-coordinate of the object may be determined.

Thus, generally, as outlined above, the optical detector, preferably theat least one evaluation device, may be adapted to individually determinez-coordinates for each of the regions or for at least one of theregions, such as for a region within the image which is recognized as apartial image, such as the image of an object. For determining the atleast one z-coordinate, the FiP-effect may be used, as outlined in oneor more of the above-mentioned prior art documents referring to theFiP-effect. Thus, the optical detector may comprise at least oneFiP-sensor, i.e. at least one optical sensor having at least one sensorregion, wherein the sensor signal of the optical sensor is dependent onan illumination of the sensor region by the light beam, wherein thesensor signal, given the same total power of the illumination, isdependent on a width of the light beam in the sensor region. Anindividual FiP-sensor may be used or, preferably, a stack ofFiP-sensors, i.e. a stack of optical sensors having the namedproperties. The evaluation device of the optical detector may be adaptedto determine the z-coordinates for at least one of the regions or foreach of the regions, by individually evaluating the sensor signal in afrequency-selective way.

In order to make use of at least one FiP-sensor within the opticaldetector, various setups may be used for combining the spatial lightmodulator, the at least one FIR-sensor and the at least one imagingdevice such as the at least one pixelated sensor, preferably the atleast one CCD or CMOS sensor. Thus, generally, the named elements may bearranged in one and the same beam path of the optical detector or may bedistributed over two or more partial beam paths. As outlined above,optionally, the optical detector may contain at least one beam-splittingelement adapted for dividing a beam path of the light beam into at leasttwo partial beam paths. Thereby, the at least one imaging device forcapturing the 2D image and the at least one FiP-sensor may be arrangedin different partial beam paths. Thus, the at least one optical sensorhaving the at least one sensor region, the sensor signal of the opticalsensor being dependent on the illumination of the sensor region by thelight beam, the sensor signal, given the same total power of theillumination, being dependent on the width of the light beam in thesensor region, (i.e. the at least one FiP-sensor) may be arranged in afirst partial beam path of the beam paths, and at least one pixelatedoptical sensor for capturing the at least one image (i.e. the at leastone imaging device), preferably the at least one inorganic pixelatedoptical sensor and more preferably the at least one of a CCD sensorand/or CMOS sensor, may arranged in a second partial beam path of thebeam paths.

The above-mentioned optional definition of the at least two regionsand/or the definition of the at least two superpixels may be performedonce or more than once. Thus, specifically, the definition of at leastone of the regions and/or of at least one of the superpixels may beperformed in an iterative way. The optical detector, preferably the atleast one evaluation device, may be adapted to iteratively refine the atleast two regions in the image or at least one of the at least tworegions within the image and, consequently, to refine the at least onecorresponding superpixel. By this iterative procedure, as an example, atleast one specific superpixel assigned to at least one object within ascene captured by the detector may be refined by identifying two or moresub-pixels, such as sub pixels corresponding to different parts of theat least one object having different z-coordinates. Thereby, by thisiterative procedure, a refined 3D image of at least one object may begenerated, since, typically, an object comprises a plurality of partshaving different orientations and/or locations in space.

The above-mentioned embodiments of the optical sensor being adapted fordefining two or more superpixels provide a large number of advantages.Thus, specifically, in a typical setup, a limited number of modulationfrequencies is available. Consequently, only a limited number of pixelsand/or modulation frequencies may be resolved by the optical detectorand may be available for distance sensing. Further, in typicalapplications, boundary regions of high contrast are necessary foraccurate distance sensing. By defining two or more superpixels and,thus, by partitioning (also referred to as tesselating) the matrix ofpixels of the spatial light modulator into superpixels, the imagingprocess may be adapted to the scene to be recorded.

The spatial light modulator specifically may have a rectangular matrixof pixels. Several pixels which may or may not be direct neighbors andwhich may form a connected area may form a superpixel. The 2D imagerecorded by the pixelated sensor, such as the CMOS and/or CCD, may beanalyzed, such as by an appropriate software, such as an imagerecognition software running on the evaluation device, and,consequently, the image may be partitioned into two or more regions. Thetessellation of the spatial light modulator may take place in accordancewith this subdividing of the image into two or more regions. As anexample, a large or very large superpixel may correspond to specificobjects within the scene recorded, such as a wall, a building, the sky,etc. Further, many small pixels or superpixels may be used to partitiona face, etc. In case a sufficient amount of superpixels are available,larger superpixels may further be partitioned into sub-pixels. The atleast two superpixels generally may differ with regard to the number ofpixels of the spatial light modulator belonging to the respectivesuperpixels. Thus, two different superpixels not necessarily have tocomprise the same number of pixels.

Generally, boundaries of the regions or superpixels may be set byarbitrary means generally known in the field of image processing andimage recognition. Thus, as an example, boundaries may be chosen bycontrast, color or intensity edges.

The definition of the two or more regions and/or the two or moresuperpixels may later on also be used for further image analysis, suchas gesture analysis, body recognition or object recognition. Exemplaryalgorithms for segmentation are Felzenszwalb's efficient graph basedsegmentation, Quickshift image segmentation, SLIC-K-Means based imagesegmentation, superpixels extracted via energy driven sampling,superpixels extracted via one or more edge detection algorithms such asa Canny algorithm, superpixels extracted via a Mean-shift algorithm suchas a Cam shift algorithm, superpixels extracted via a Contour extractionalgorithm, superpixels extracted via edge, ridge, corner, blob, orfeature detection, superpixels extracted via dimensionality reduction,superpixels obtained by texture classification and superpixels obtainedby using texture segmentation. Combinations of the named techniquesand/or other techniques are possible.

The superpixelation may also change during image recording. Thus, arough pixelation into superpixels may be chosen for quick distancesensing. A finer grid or superpixelation may then be chosen for a moredetailed analysis and/or in case high distance gradients are recognizedin between two neighboring superpixels and/or in case high gradients inone or more of contrast, color, intensity or the like are noticed inbetween two neighboring superpixels. A high resolution 3D-image may thusbe recorded in an iterative approach where the first image has a roughresolution, the next image has a refined resolution etc.

The above-mentioned options of determining one or more regions andassigning one or more superpixels to these regions may further be usedfor eye tracking. Thus, in many applications such as safety applicationsand/or entertainment applications, determining the position and/ororientation of eyes of a user, another person or another creature mayplay an important role. As an example, in entertainment applications,the perspective of the viewer plays a role. For instance 3D-visionapplications, the perspective of the viewer may change the setup of animage. Therefore, it may be a significant interest to know and/or trackthe viewing position of an observer. In safety applications such asautomotive safety applications, the detection of animals is ofimportance, in order to avoid collisions.

The above-mentioned definition of one, two or more superpixels mayfurther be used to improve or even optimize light conditions. Thus,generally, the frequency response of an optical sensor typically leadsto weaker sensor signals when higher modulation frequencies are used,such as higher modulation frequencies of the SLM, specifically of theDLP. Areas with high light intensities within the image and/or scene maytherefore be modulated with high frequencies, whereas areas with lowlight intensities may be modulated with low frequencies.

In order to make use of this effect, the optical detector may be adaptedto detect at least one first area within the image, the first areahaving a first illumination, such as a first average illumination, andthe optical detector may further be adapted to detect at least onesecond area within the image, the second area having a secondillumination, such as a second average illumination, wherein the secondillumination is lower than the first illumination. The first area may beassigned to at least one first superpixel, and the second area may beassigned to at least one second superpixel. In other words, the opticaldetector may be adapted to choose at least two superpixels according tothe illumination of a scene or an image of the scene captured by theoptical detector.

The optical detector may further be adapted to modulate the pixels ofthe at least two superpixels according to their illumination. Thus,superpixels having a higher illumination may be modulated at highermodulation frequencies, and superpixels having a lower illumination maybe modulated at lower modulation frequencies. In other words, theoptical detector may further be adapted to modulate the pixels of thefirst superpixel with at least one first modulation frequency, and theoptical detector may further be adapted to modulate the pixels of thesecond superpixel with at least one second modulation frequency, whereinthe first modulation frequency is higher than the second modulationfrequency. Other embodiments are feasible. The optical detectoraccording to the present invention may therefore be adapted to detect atleast one eye and preferably to track the position and/or orientation ofat least one eye or of eyes.

A simple solution to detect the viewing position of an observer or theposition of an animal is to make use of a modulated eye reflection. Alarge number of mammals possess a reflective layer behind the retina,the so-called tapetum lucidum. The tapetum lucidum reflection is ofslightly different color appearance for different animals, but mostreflect well in the green visible range. The tapetum lucidum reflectiongenerally allows for making animals visible in the dark over fardistances, using simple diffuse light sources.

Humans generally do not possess a tapetum lucidum. However, inphotographs, the so-called heme-emission induced by a photography flashis often recorded, also referred to as the “red-eye effect”. This effectmay also be used for eye detection of human beings, even though it isnot directly visible to the human eye, due to the human eye's lowsensitivity in the spectral range beyond 700 nm. The red-eye effect mayspecifically be induced by modulated red illumination and sensed by atleast one optical sensor of the optical detector, such as at least oneFiP-sensor, wherein the at least one optical sensor is sensitive at theheme-emission wavelength.

The optical detector according to the present invention may thereforecomprise at least one illumination source, also referred to as at leastone light source, which may be adapted to fully or partially illuminatea scene captured by the optical detector, wherein the light source isadapted to evoke reflections in a mammal, such as in a tapetum lucidumof a mammal and/or is adapted to evoke the above-mentioned red-eyeeffect in human eyes. Specifically, the light in the infrared spectralrange, the red spectral range, the yellow spectral range, the greenspectral range, the blue spectral range or simply white light may beused. Still, other spectral ranges and/or broadband light sources may beused additionally or alternatively.

Additionally or alternatively, the eye detection may also take placewithout a dedicated illumination source. As an example, ambient light orother light from light sources such as lanterns, streetlights orheadlights of a car or other vehicle may be used and may be reflected bythe eye.

In case at least one illumination source is used, the at least oneillumination source may continuously emit light or may be a modulatedlight source. Thus, specifically, at least one modulated active lightsource may be used.

The reflection specifically may be used in order to detect animalsand/or humans over large distances, such as by using a modulated activelight source. The at least one optical sensor, specifically the at leastone FiP sensor, may be used for measuring at least one longitudinalcoordinate of the eye, such as by evaluating the above mentionedFiP-effect of the eye reflections. This effect specifically may be usedin car safety applications, such as in order to avoid collisions withhumans or animals. A further possible application is the positioning ofobservers for entertainment devices, especially if using 3D-vision,especially if the 3D-vision is dependent on the viewing angle of theobserver.

As outlined above or as outlined in further detail in the following, thedevices according to the present invention, such as the opticaldetector, may be adapted to identify and/or track one or more objectswithin an image and/or within a scene captured by the optical detector,specifically by assigning one or more superpixels to the at least oneobject. Further, two or more parts of the object may be identified, andby determining and/or tracking the longitudinal and/or transversalposition of these parts within the image, such as the relativelongitudinal and/or transversal position, at least one orientation ofthe object may be determined and/or tracked. Thus, as an example, bydetermining two or more wheels of a vehicle within the image and bydetermining and/or tracking the position, specifically the relativeposition, of these wheels, an orientation of the vehicle and/or a changeof orientation of the vehicle may be determined, such as calculated,and/or tracked. For example, in a car, the distance between the wheelsis generally known or it is known that the distance between the wheelsdoes not change. Further it is generally known that the wheels arealigned on a rectangle. Detecting the position of the wheels thus allowscalculating the orientation of the vehicle such as a car, a plane or thelike.

In a further example, as outlined above, the position of eyes may bedetermined and/or tracked. Thus, the distance and/or position of theeyes or parts thereof, such as the pupils, and/or other facial featurescan be used for eye trackers or to determine in which direction a faceis oriented.

As outlined above, the at least one light beam may fully or partiallyoriginate from the object itself and/or from at least one additionalillumination source, such as an artificial illumination source and/or anatural illumination source. Thus, the object may be illuminated with atleast one primary light beam, and the actual light beam propagatingtowards the optical detector may be or may comprise a secondary lightbeam generated by reflection, such as elastic and/or inelasticreflection, of the primary light beam at the object and/or byscattering. Non-limiting examples of objects which are detectable byreflections are reflections of sunlight, artificial light in eyes, onsurfaces, etc. Non-limiting examples of objects from which the at leastone light beam originates fully or partially from the object itself areengine exhausts in cars or planes. As outlined above, eye reflectionsmight be especially useful for eye-trackers.

Further, as outlined above, the optical detector comprises at least onemodulator device, such as an SLM. The optical detector, however,additionally or alternatively may make use of a given modulation of thelight beam. Thus, in many instances, the light beam already exhibits agiven modulation. The modulation, as an example, may originate from amovement of the object, such as a periodic modulation, and/or from amodulation of a light source or illumination source generating the lightbeam. Thus, as non-limiting examples for moving objects adapted togenerate modulated light such as by reflection and/or scattering areobjects that are modulated by itself, such as rotors of wind turbines orplanes. Non-limiting examples of illumination sources adapted togenerate modulated light are fluorescent lamps or reflections offluorescent lamps. The optical detector may be adapted to detect givenmodulations of the at least one light beam. As an example, the opticaldetector may be adapted to determine at least one object or at least onepart of an object within an image or a scene captured by the opticaldetector that emits or reflects modulated light, such as light having,by itself and without any influence of the SLM, at least one modulationfrequency. If this is the case, the optical detector may be adapted tomake use of this given modulation, without additionally modulating thealready modulated light. As an example, the optical detector may beadapted to determine if at least one object within an image or a scenecaptured by the optical detector emits or reflects modulated light. Theoptical detector, especially the evaluation device, may further beadapted to assign at least one superpixel to said object, wherein thepixels of the superpixel specifically may not be modulated, in order toavoid a further modulation of light originating or being reflected bysaid object. The optical detector, specifically the evaluation device,may further be adapted to determine and/or track the position and/ororientation of said object by using the modulation frequency. Thus, asan example, the detector may be adapted to avoid modulation for theobject, such as by switching the modulation device to an “open”position. The evaluation device could then track the frequency of thelamp.

The spatial light modulator may be used for a simplified image analysisof at least one image captured by an image detector and/or for ananalysis of a scene captured by the optical detector. Thus, generally, acombination of the at least one spatial light modulator and at least onelongitudinal optical sensor may be used, such as a combination of atleast one FiP sensor and at least one spatial light modulator such as aDLP. The analysis may be performed by using an iterative scheme. If afocus point causing a FiP-signal is part of a larger region on thelongitudinal optical sensor, the FiP signal may be detected. The spatiallight modulator may separate an image or a scene captured by the opticaldetector into two or more regions. If a FiP-effect is measured in atleast one of the regions, the regions may further be subdivided. Thissubdivision may be continued until a maximum number of possible regions,which may be limited by the maximum number of available modulationfrequencies of the spatial light modulator, is reached. More complexpatterns are also possible.

As outlined above, the optical detector generally may comprise at leastone imaging device and/or may be adapted to capture at least one image,such as at least one image of a scene within a field of view of theoptical detector. By using one or more image evaluation algorithms, suchas generally known pattern detection algorithms and/or software imageevaluation means generally known to the skilled person, the opticaldetector may be adapted to detect at least one object in the at leastone image. Thus, as an example, in traffic technology, the detector and,more specifically, the evaluation device, may be adapted to search forspecific predefined patterns within an image, such as one or more of thefollowing: the contour of a car; the contour of another vehicle; thecontour of a pedestrian; street signs; signals; landmarks fornavigation. The detector may also be used in combination with global orlocal positioning systems. Similarly, for biometrical purposes such asfor the purpose of recognition and/or tracking of persons, the detectorand, more specifically, the evaluation device, may be adapted forsearching a contour of a face, eyes, earlobes, lips, noses or profilesthereof. Other embodiments are feasible.

In case one or more objects are detected, the optical detector might beadapted to track the object in a series of images, such as an ongoingmovie or film of the scene. Thus, generally, the optical detector,specifically the evaluation device, may be adapted to track and/orfollow the at least one object within a series of images, such as aseries of subsequent images.

For the purpose of object following, the optical detector may be adaptedto assign the at least one object to a region within the image or seriesof images, as described above. As discussed earlier, the opticaldetector, preferably the at least one evaluation device, may be adaptedto assign at least one superpixel of the matrix of pixels of the spatiallight modulator to the at least one region corresponding to the at leastone object. By modulating the pixels of the superpixels in a specificway, such as by using a specific modulation frequency, the object may betracked, and the at least one z-coordinates of the at least one objectmay be followed by using the at least one optional longitudinal sensor,such as the at least one FiP-detector, and demodulating or isolating thecorresponding signals of the longitudinal sensor, such as the at leastone FiP-detector, according to this specific modulation frequency. Theoptical detector may be adapted to adjust the assignment of the at leastone superpixel for the images of the series of images. Thus, as anexample, the imaging device may continuously acquire images of the sceneand, for each image, the at least one object may be recognized.Subsequently, the at least one superpixel may be assigned to the object,and the z-coordinate of the object may be determined by using the atleast one longitudinal optical sensor, specifically the at least oneFiP-sensor, before turning to the next image. Thus, the at least oneobject may be followed in space.

This embodiment allows for a greatly simplified setup of the opticaldetector. The optical detector may be adapted to perform an analysis ofa scene captured by the imaging device, such as a standard 2D-CCDcamera. A picture analysis of the scene can be used to recognizepositions of active and/or passive objects. The optical detector may betrained to recognize specific objects, such as predetermined patterns orsimilar patterns. In case one or more objects are recognized, thespatial light modulator may be adapted to modulate only the regions inwhich the one or more objects are located and/or to modulate theseregions in a specific fashion. The remaining area may remain unmodulatedand/or may be modulated in a different way, which may generally be knownto the Longitudinal sensor and/or to the evaluation device.

By using this effect, the number of modulation frequencies used by thespatial light modulator may be greatly reduced. Typically, only alimited number of modulation frequencies is available to analyze thefull scene. If only the important or recognized objects are followed, avery small number of frequencies are necessary.

The longitudinal optical sensor or distance sensor can then be used asunpixelated large area sensor or as a large area sensor having only asmall number of superpixels, such as at least one superpixelcorresponding to the at least one object and a remaining superpixelcorresponding to the surrounding area, wherein the latter may remainunmodulated. Thus, the number of modulation frequencies and thus thecomplexity of the data analysis of the sensor signal may greatly bereduced as compared to the basic SLM detector of the present invention.

As outlined above, this embodiment specifically may be used in traffictechnology and/or for biometric purposes, such as identification and/orof persons and/or for the purpose of eye tracking. Other applicationsare feasible.

The optical detector according to the present invention may further beembodied to acquire three-dimensional images. Thus, specifically, asimultaneous acquisition of images in different planes perpendicular toan optical axis may be performed, i.e. an acquisition of images indifferent focal planes. Thus, specifically, the optical detector may beembodied as a light-field camera adapted for acquiring images inmultiple focal planes, such as simultaneously. The term light-field, asused herein, generally refers to the spatial light propagation of lightinside the camera. Contrarily, in commercially available plenoptic orlight-field cameras, micro-lenses may be placed on top of an opticaldetector. These micro-lenses allow for recording a direction of lightbeams, and, thus, for recording pictures in which a focus may be changeda posteriori. However, the resolution of a camera with micro-lenses isgenerally reduced by approximately a factor of ten as compared toconventional cameras. A post-processing of the images is required inorder to calculate pictures which are focused on various distances.Another disadvantage of current light-field cameras is the necessity ofusing a large number of micro-lenses which typically have to bemanufactured on top of an imaging chip such as a CMOS chip.

By using the optical detector according to the present invention, agreatly simplified light-field camera may be produced, without thenecessity of using micro-lenses. Specifically, a single lens or lenssystem may be used. The evaluation device may be adapted for intrinsicdepth-calculation and simple and intrinsic creation of a picture that isfocused on a plurality of levels or even on all levels.

These advantages may be achieved by using a multiplicity of the opticalsensors. Thus, as outlined above, the optical detector may comprise atleast one stack of optical sensors. The optical sensors of the stack orat least several of the optical sensors of the stack preferably are atleast partially transparent. Thus, as an example, pixilated opticalsensors or large area optical sensors may be used within the stack. Asan example for potential embodiments of optical sensors, reference maybe made to the organic optical sensors, specifically to the organicsolar cells and, more specifically, to the DSC optical sensors or sDSCoptical sensors as disclosed above or as disclosed in further detailbelow. Thus, as an example, the stack may comprise a plurality of FPsensors as disclosed e.g. in WO 2012/110924 A1 or in any other of theFiP-related documents discussed above, i.e. a plurality of opticalsensors with photon density-dependent photocurrents for depth detection.Thus, specifically, the stack may be a stack of transparentdye-sensitized organic solar cells. As an example, the stack maycomprise at least two, preferably at least three, more preferably atleast four, at least five, at least six or even more optical sensors,such as 2-30 optical sensors, preferably 4-20 optical sensors. Otherembodiments are feasible. By using the stack of optical sensors, theoptical detector, specifically the at least one evaluation device, maybe adapted to acquire a three-dimensional image of a scene within afield of view of the optical detector, such as by acquiring images atdifferent focal depths, preferably simultaneously, wherein the differentfocal depths generally may be defined by a position of the opticalsensors of the stack along an optical axis of the optical detector. Eventhough a pixelation of the optical sensors generally may be present, apixelation is, however, generally unnecessary due to the fact that theuse of the at least one spatial light modulator allows for a virtualpixelation, as outlined above. Thus, as an example, a stack of organicsolar cells, such as a stack of sDSCs, may be used, without thenecessity of subdividing the organic solar cells into pixels.

Thus, specifically for use as a light-field camera and/or foracquisition of three-dimensional images, the optical detector maycomprise the at least one stack of optical sensors and the at least onespatial light modulator, the latter of which may be or may comprise atleast one transparent spatial light modulator and/or at least onereflective spatial light modulator, as outlined above. Further, theoptical detector may comprise at least one transfer device, specificallyat least one lens or lens system. Thus, as an example, the opticaldetector may comprise at least one camera lens, specifically at leastone camera lens for imaging a scene, as known in the field ofphotography.

The setup of the optical detector as disclosed above specifically may bearranged and ordered as follows (listed in a direction towards theobject or scene to be detected):

-   -   (1) at least one stack of optical sensors, such as a stack of        transparent or semitransparent optical sensors, more        specifically a stack of solar cells, such as organic solar cells        like sDSCs, preferably without pixels with photon        density-dependent photocurrents for depth detection;    -   (2) at least one spatial light modulator, preferably with high        resolution pixels and high frequency for switching pixels, such        as a transparent or reflective spatial light modulator;    -   (3) at least one transfer device, such as at least one lens or        lens system, more preferably at least one suitable camera lens        system.

Additional devices may be comprised, such as one or more beam splitters.Further, as outlined above, in this embodiment or other embodiments, theoptical detector may comprise one or more optical sensors embodied as animaging device, wherein monochrome, multi-chrome or full-color imagingdevices may be used. Thus, as an example, the optical detector mayfurther comprise at least one imaging device such as at least one CCDchip and/or at least one CMOS chip. The at least one imaging device, asoutlined above, specifically may be used for acquiring two-dimensionalimages and/or for recognition of objects within a scene captured by theoptical detector.

As outlined in further detail above, the pixels of the spatial lightmodulator may be modulated. Therein, the pixels may be modulated atdifferent frequencies and/or the pixels may be grouped into at least twogroups of pixels corresponding to the scene, such as for the purpose offorming superpixels. In this regard, reference may be made to thepossibilities disclosed above. The information for the pixels may beattained by using differing modulation frequencies. For details,reference may be made to the possibilities discussed above.

In general, a depth map may be recorded by using signals produced by thestack of optical sensors and, additionally, by recording atwo-dimensional image by using the at least one optional imaging device.A plurality of two-dimensional images at different distances from thetransfer device, such as from the lens, may be recorded. Thus, a depthmap may be recorded by a stack of solar cells, such as a stack oforganic solar cells, and by further recording a two-dimensional image byusing the imaging device such as the at least one optional CCD chipand/or CMOS chip. The two-dimensional image may then be matched with thesignals of the stack in order to obtain a three-dimensional image.Additionally or alternatively, however, the recording of athree-dimensional image may also take place without the use of animaging device such as a CCD chip and/or a CMOS chip. Thus, each opticalsensor or two or more of the optical sensors of the stack of opticalsensors may be used for recording two-dimensional images each, by usingthe above-mentioned process implying the spatial light modulator. Thisis possible, since by SLM-modulation, information on pixel position,size and brightness may be known. By evaluating sensor signals of theoptical sensors, such as by demodulating the sensor signals and/or byperforming a frequency analysis as discussed above, two-dimensionalpictures may be derived from each optical sensor signal. Thereby, atwo-dimensional image for each of the optical sensors may bereconstructed. Using a stack of optical sensors, such as a stack oftransparent solar cells, therefore allows for recording two-dimensionalimages acquired at different positions along an optical axis of theoptical detector, such as at different focal positions. The acquisitionof the plurality of two-dimensional optical images may be performedsimultaneously and/or instantaneously. Thus, by using the stack ofoptical sensors in combination with the spatial light modulator, asimultaneous “tomography” of the optical situation may be acquired.Thereby, a light-field camera without micro-lenses may be realized.

The optical detector even allows for further post-processing of theinformation acquired by using the spatial light modulator and the stackof optical sensors. As compared to other sensors, however, for obtaininga three-dimensional image of a scene, little post-processing or even nopost-processing may be required. Still, fully focused pictures can beobtained.

Further, use may be made of the possibility that one, more than one oreven all of the optical sensors of the stack of optical sensors may beFiP sensors, i.e. optical sensors having a photon-density dependentsensor signal, i.e. optical sensors providing sensor signals beingdependent on an illumination of a sensor region by a light beam, whereinthe sensor signal, given the same total power of the illumination, isdependent on a width of the light beam in the sensor region. Whenchanging the focus of a light beam illuminating the sensor region, thesensor signal, such as the photocurrent, for the respective opticalsensor being designed as a FiP sensor reaches a maximum for a minimumdiameter of the spot of illumination, i.e. as soon as the light beam isfocused in the sensor region. Thus, the sensor signals of the opticalsensors of the stack of optical sensors may indicate a focal position ofa light beam since, generally, the optical sensor having the largestsensor signal may indicate a focal plane for the light beam. In case thelight beam is emitted by an object within a scene captured by theoptical detector, the light beam optionally will be imaged by the atleast one optional transfer device such as the at least one lens or lenssystem and finally may be focused onto a position within the stack ofoptical sensors. By evaluating and comparing the sensor signals, such asby detecting the maximum sensor signal, the focal position may bedetermined. Generally, if a picture is constructed from the pixelinformation having a maximum in the sensor signal, corresponding to amaximum of the FIP-curve, the reconstructed picture may be focused inall image planes.

Further, the optical detector according to the present invention mayavoid or at least partially circumvent typical problems of correctingimaging errors such as lens errors. Thus, in many optical devices suchas microscopes or telescopes, lens errors may cause significantproblems. As an example, in microscopes, a common lens error is thewell-known error of spherical aberration, which leads to the phenomenonthat the refraction of light rays may depend on the distance from anoptical axis. Further, temperature effects may occur, such as atemperature-dependency of a focal position in a telescope. Static errorsgenerally may be corrected by determining the error once and using afixed set of SLM-pixel/solar cell combinations to construct a focusedimage. In case the optical system remains identical, in many cases, asoftware adjustment may be sufficient. Still, specifically in cases oferrors changing over time, these conventional corrections may not besufficient any longer. In this case, by using the optical detectoraccording to the present invention having at least one spatial lightmodulator and at least one stack of optical sensors may be used forintrinsically correcting the error, specifically automatically, byacquiring an image in the correct focal plane.

The above-mentioned concept of the optical detector having a stack ofoptical sensors at different z-positions provides further advantagesover current light-field cameras. Thus, typical light-field cameras arepicture-based or pixel-based, in that a picture at a certain distancefrom the lens is reconstructed. The information to be stored typicallyis linearly dependent on the number of pixels and on the number ofpictures. Contrarily, the optical detector according to the presentinvention, specifically having a stack of optical sensors in combinationwith at least one spatial light modulator, may have the capability ofdirectly recording a light-field within the optical detector or camera,such as behind a lens. Thus, the optical detector generally may beadapted for recording one or more beam parameters for one or more lightbeams entering the optical detector. As an example, for each of thelight beams, one or more beam parameters such as Gaussian beamparameters may be recorded, such as a focal point, a direction, and aspread-function width. Therein, the focal point may be the point orcoordinate at which the beam is focused, and the direction may provideinformation regarding the spreading or propagation of the light beam.Other beam parameters may be used alternatively or additionally. Thespread-function width may be the width of the function that describesthe beam outside its focal point. The spread function may be a Gaussianfunction in simple cases, and the width parameter may be the exponent ofthe Gaussian function or a part of the exponent.

Thus, generally, the optical detector according to the present inventionmay allow for directly recording one or more beam parameters of the atleast one light beam, such as at least one focal point of light beams,their propagation direction and their spread parameters. These beamparameters may directly be derived from an analysis of one or moresensor signals of the optical sensors of the stack of optical sensors,such as from an analysis of the FiP-signals. The optical detector, whichspecifically may be designed as a camera, thus may record a vectorrepresentation of the light-field which may be compact and scalable,and, thus, may include more information as compared to a two-dimensionalpicture and a depth map.

Thus, a focal stacking camera and/or a focal sweep camera may recordpictures at different cut-planes of the light-field. The information maybe stored as number of pictures times a number of pixels. Contrarily,the optical detector according to the present invention, specificallythe optical detector comprising a stack of optical sensors and at leastone spatial light modulator, more specifically a stack of FiP-sensorsand a spatial light modulator, may be adapted for storing theinformation as number of beam parameters, such as the above-mentioned atleast one spread parameter, the focal point, and the propagationdirection, for each light beam. Thus, generally, pictures in between theoptical sensors may be calculated from the vector representation. Thus,generally, an interpolation or extrapolation may be avoided. A vectorrepresentation generally has very low need for data storage space, ascompared e.g. to the storage space required for known light-fieldcameras based on a pixel representation. Further, the vectorrepresentation may be combined with image compression methods known tothe person skilled in the art. Such a combination with image compressingmethods may further reduce the storage requirements for the recordedlight-field. Compression methods may be one or more of color spacetransformation, down-sampling, chain codes, Fourier-related transforms,block splitting, discrete cosine transform, fractal compression, chromesubsampling, quantization, deflation, DPCM, LZW, entropy coding, wavelettransform, jpeg compression or further lossless or lossy compressionmethods.

Consequently, the optical detector including the at least one spatiallight modulator and the stack of optical sensors may be adapted todetermine at least one, preferably at least two or more beam parametersfor at least one light beam, preferably for two beams or more than twolight beams, and may be adapted to store these beam parameters forfurther use. Further, the optical detector, specifically the evaluationdevice, may be adapted for calculating images or partial images of ascene captured by the optical detector by using these beam parameters,such as by using the above-mentioned vector representation. Due to thevector representation, the optical detector designed as a light-fieldcamera may also detect and/or calculate the field between the pictureplanes defined by the optical sensors.

Further, the optical detector, specifically the evaluation device, maybe designed to take into account the position of an observer and/or aposition of the optical detector itself. This is due to the fact thatall information or almost all information entering the detector throughthe transfer device such as through the at least one lens may bedetected by the optical detector, such as the light-field camera.Similar to a hologram, providing insight into part of a space behind anobject, the light-field as detected or detectable by the opticaldetector having the stack of optical sensors and the at least onespatial light modulator, specifically given the above-mentioned beamparameter or vector representation, may contain additional informationsuch as information regarding a situation in which an observer moveswith respect to a fixed camera lens. Thus, due to the known propertiesof the light-field, a cross-sectional plane through the light-field maybe moved and/or tilted. Additionally or alternatively, even non-planarcross-sections through the light-field may be generated. The latterspecifically may be beneficial for correcting lens errors. When aposition of an observer is moved, such as a position of an observer in acoordinate system of the optical detector, the visibility of one or moreobjects may change, such as in case a second object becomes visiblebehind a first object.

The optical detector, as outlined above, may be a monochrome, amulti-chrome or even a full-color optical detector. Thus, as outlinedabove, color sensitivity may be generated by using at least onemulti-chrome or full-color spatial light modulator. Additionally oralternatively, in case two or more optical sensors are comprised, thetwo or more optical sensors may provide different spectralsensitivities. Specifically, in case a stack of optical sensors is used,specifically a stack of one or more optical sensors selected from thegroup consisting of solar cells, organic solar cells, dye sensitizedsolar cells, solid dye sensitized solar cells or FiP sensors in general,color sensitivity may be generated by using optical sensors havingdiffering spectral sensitivities. Specifically in case a stack ofoptical sensors is used, comprising two or more optical sensors, theoptical sensors may have differing spectral sensitivities such asdiffering absorption spectra.

Thus, generally, the optical detector may comprise a stack of opticalsensors, wherein the optical sensors of the stack have differingspectral properties. Specifically, the stack may comprise at least onefirst optical sensor having a first spectral sensitivity and at leastone second optical sensor having a second spectral sensitivity, whereinthe first spectral sensitivity and the second spectral sensitivity aredifferent. The stack, as an example, may comprise optical sensors havingdiffering spectral properties in an alternating sequence. The opticaldetector may be adapted to acquire a multicolor three-dimensional image,preferably a full-color three-dimensional image, by evaluating sensorsignals of the optical sensors having differing spectral properties.

This option of color resolution provides a large number of advantagesover known color sensitive camera setups. Thus, by using optical sensorsin a stack, the optical sensors having differing spectral sensitivities,the full sensor area of each sensor may be used for detection, ascompared to a pixelated full-color camera such as full-color CCD or CMOSchips. Thereby, the resolution of the images may significantly beincreased, since typical pixelated full-color camera chips may only useone third or one fourth or even less of the chip surface for imaging,due to the fact that colored pixels have to be provided in a neighboringarrangement.

The at least two optical sensors having differing spectral sensitivitiesmay contain different types of dyes, specifically when using organicsolar cells, more specifically sDSCs. Therein, stacks containing two ormore types of optical sensors, each type having a uniform spectralsensitivity, may be used. Thus, the stack may contain at least oneoptical sensor of a first type, having a first spectral sensitivity, andat least one optical sensor of a second type, having a second spectralsensitivity. Further, the stack may optionally contain a third type andoptionally even a fourth type of optical sensors having third and fourthspectral sensitivities, respectively. The stack may contain opticalsensors of the first and second type in an alternating fashion, opticalsensors of the first, second and third type in an alternating fashion oreven sensors of the first, second, third and fourth type in analternating fashion.

As it turns out, a color detection or even an acquisition of full-colorimages may be possible with optical sensors of a first type and a secondtype, only, such as in an alternating fashion. Thus, as an example, thestack may contain organic solar cells, specifically sDSCs, of a firsttype, having a first absorbing dye, and organic solar cells,specifically sDSCs, of a second type, having a second absorbing dye. Theorganic solar cells of the first and second type may be arranged in analternating fashion within the stack. The dyes specifically may bebroadly absorbing, such as by providing an absorption spectrum having atleast one absorption peak and the broad absorption covering a range ofat least 30 nm, preferably of at least 100 nm, of at least 200 nm or ofat least 300 nm, such as having a width of 30-200 nm and/or a width of60-300 nm and or a width of 100-400 nm.

Thus, two broadly absorbing dyes may be sufficient for color detection.Using two broadly absorbing dyes with different absorption profiles in atransparent or semi-transparent solar cell, different wavelengths willcause different sensor signals such as different currents, due to thecomplex wavelength dependency of the photon-to-current efficiency (PCE).The color can be determined by comparing the currents of two solar cellswith different dyes.

Thus, generally, the optical detector having the stack of opticalsensors with at least two optical sensors having different spectralsensitivities, may be adapted to determine at least one color and/or atleast one item of color information by comparing sensor signals of theat least two optical sensors having different spectral sensitivities. Asan example, an algorithm may be used for determining the color of colorinformation from the sensor signals. Additionally or alternatively,other ways of evaluating the sensor signals may be used, such as alookup tables. As an example, a look-up table can be created in which,for each pair of sensor signals, such as for each pair of currents, aunique color is listed. Additionally or alternatively, other evaluationschemes may be used, such as by forming a quotient of the optical sensorsignals and deriving a color, a color information or color coordinatethereof.

By using a stack of optical sensors having differing spectralsensitivities, such as a stack of pairs of optical sensors having twodifferent spectral sensitivities, a variety of measurements may betaken. Thus, as an example, by using the stack, a recording of athree-dimensional multicolor or even full-color image is feasible,and/or a recording of an image in several focal planes. Further, depthimages can be calculated using depth from-defocus algorithms.

By using two types of optical sensors having differing spectralsensitivities, a missing color information may be extrapolated betweensurrounding color points. A smoother function can be obtained by takingmore than only surrounding points into account. This may also be usedfor reducing measurement errors, while computational costs forpost-processing increase.

Generally, the optical detector according to the present invention maythus be designed as a multicolor or full-color or color-detectinglight-field camera. A stack of alternatingly colored optical sensors,such as transparent or semi-transparent solar cells, specificallyorganic solar cells and more specifically sDSCs, may be used. Theseoptical detectors are used in combination with the at least one spatiallight-modulator, such as for the purpose of providing a virtualpixelation. Thus, the optical detectors may be large-area opticaldetectors without pixelation, wherein the pixelation is virtuallycreated by the spatial light modulator and an evaluation, specifically afrequency analysis, of the sensor signals of the optical sensors.

Color information in-plane may be obtained from sensor signals of twoneighboring optical sensors of the stack, neighboring optical sensorshaving different spectral sensitivity, such as different colors, morespecifically different types of dyes. As outlined above, the colorinformation may be generated by an evaluation algorithm evaluating thesensor signals of the optical sensors having different wavelengthsensitivities, such as by using one or more look-up tables. Further, asmoothing of the color information may be performed, such as in apost-processing step, by comparing colors of neighboring areas.

The color information in z-direction, i.e. along the optical axis, canalso be obtained by comparing neighboring optical sensors and the stack,such as neighboring solar cells in the stack. Smoothing of the colorinformation can be done using color information from several opticalsensors.

The optical detector according to the present invention, comprising atleast one spatial light modulator and at least one optical sensor, mayfurther be combined with one or more other types of sensors ordetectors. Thus, the optical detector may further comprise at least oneadditional detector. The at least one additional detector may be adaptedfor detecting at least one parameter, such as at least one of: aparameter of a surrounding environment, such as a temperature and/or abrightness of a surrounding environment; a parameter regarding aposition and/or orientation of the detector; a parameter specifying astate of the object to be detected, such as a position of the object,e.g. an absolute position of the object and/or an orientation of theobject in space. Thus, generally, the principles of the presentinvention may be combined with other measurement principles in order togain additional information and/or in order to verify measurementresults or reduce measurement errors or noise.

Specifically, the optical detector according to the present inventionmay further comprise at least one time-of-flight (ToF) detector adaptedfor detecting at least one distance between the at least one object andthe optical detector by performing at least one time-of-flightmeasurement. As used herein, a time-of-flight measurement generallyrefers to a measurement based on a time a signal needs for propagatingbetween two objects or from one object to a second object and back. Inthe present case, the signal specifically may be one or more of anacoustic signal or an electromagnetic signal such as a light signal. Atime-of-flight detector consequently refers to a detector adapted forperforming a time-of-flight measurement. Time of flight measurements arewell-known in various fields of technology such as in commerciallyavailable distance measurement devices or in commercially available flowmeters, such as ultrasonic flow meters. Time-of-flight detectors evenmay be embodied as time-of-flight cameras. These types of cameras arecommercially available as range-imaging camera systems, capable ofresolving distances between objects based on the known speed of light.

Presently available ToF detectors generally are based on the use of apulsed signal, optionally in combination with one or more light sensorssuch as CMOS-sensors. A sensor signal produced by the light sensor maybe integrated. The integration may start at two different points intime. The distance may be calculated from the relative signal intensitybetween the two integration results.

Further, as outlined above, ToF cameras are known and may generally beused, also in the context of the present invention. These ToF camerasmay contain pixelated light sensors. However, since each pixel generallyhas to allow for performing two integrations, the pixel constructiongenerally is more complex and the resolutions of commercially availableToF cameras is rather low (typically 200×200 pixels). Distances below˜40 cm and above several meters typically are difficult or impossible todetect. Furthermore, the periodicity of the pulses leads to ambiguousdistances, as only the relative shift of the pulses within one period ismeasured.

ToF detectors, as standalone devices, typically suffer from a variety ofshortcomings and technical challenges. Thus, in general, ToF detectorsand, more specifically, ToF cameras suffer from rain and othertransparent objects in the light path, since the pulses might bereflected too early, objects behind the raindrop are hidden, or inpartial reflections the integration will lead to erroneous results.Further, in order to avoid errors in the measurements and in order toallow for a clear distinction of the pulses, low light conditions arepreferred for ToF-measurements. Bright light such as bright sunlight canmake a ToF-measurement impossible. Further, the energy consumption oftypical ToF cameras is rather high, since pulses must be bright enoughto be back-reflected and still be detectable by the camera. Thebrightness of the pulses, however, may be harmful for eyes or othersensors or may cause measurement errors when two or more ToFmeasurements interfere with each other. In summary, current ToFdetectors and, specifically, current ToF-cameras suffer from severaldisadvantages such as low resolution, ambiguities in the distancemeasurement, limited range of use, limited light conditions, sensitivitytowards transparent objects in the light path, sensitivity towardsweather conditions and high energy consumption. These technicalchallenges generally lower the aptitude of present ToF cameras for dailyapplications such for safety applications in cars, cameras for daily useor human-machine-interfaces, specifically for use in gamingapplications.

In combination with the detector according to the present invention,providing at least one spatial light modulator and at least one opticalsensor as well as the above-mentioned principle of evaluating the sensorsignal by frequency analysis, the advantages and capabilities of bothsystems may be combined in a fruitful way. Thus, the SLM detector, i.e.the combination of the at least one spatial light modulator and the atleast one optical sensor, specifically the at least one stack of opticalsensors, may provide advantages at bright light conditions, while theToF detector generally provides better results at low-light conditions.A combined device, i.e. an optical detector according to the presentinvention further including at least one ToF detector, thereforeprovides increased tolerance with regard to light conditions as comparedto both single systems. This is especially important for safetyapplications, such as in cars or other vehicles.

Specifically, the optical detector may be designed to use at least oneToF measurement for correcting at least one measurement performed byusing the SLM detector and vice a versa. Further, the ambiguity of a ToFmeasurement may be resolved by using the SLM detector. An SLMmeasurement specifically may be performed whenever an analysis of ToFmeasurements results in a likelihood of ambiguity. Additionally oralternatively, SLM measurements may be performed continuously in orderto extend the working range of the ToF detector into regions which areusually excluded due to the ambiguity of ToF measurements. Additionallyor alternatively, the SLM detector may cover a broader or an additionalrange to allow for a broader distance measurement region. The SLMdetector, specifically the SLM camera, may further be used fordetermining one or more important regions for measurements to reduceenergy consumption or to protect eyes. Thus, as outlined above, the SLMdetector may be adapted for detecting one or more regions of interest.Additionally or alternatively, the SLM detector may be used fordetermining a rough depth map of one or more objects within a scenecaptured by the optical detector, wherein the rough depth map may berefined in important regions by one or more ToF measurements. Further,the SLM detector may be used to adjust the ToF detector, such as the ToFcamera, to the required distance region. Thereby, a pulse length and/ora frequency of the ToF measurements may be pre-set, such as for removingor reducing the likelihood of ambiguities in the ToF measurements. Thus,generally, the SLM detector may be used far providing an autofocus forthe ToF detector, such as for the ToF camera.

As outlined above, a rough depth map may be recorded by the SLMdetector, such as the SLM camera. Further, the rough depth map,containing depth information or z-information regarding one or moreobjects within a scene captured by the optical detector, may be refinedby using one or more ToF measurements. The ToF measurements specificallymay be performed only in important regions. Additionally oralternatively, the rough depth map may be used to adjust the ToFdetector, specifically the ToF camera.

Further, the use of the SLM detector in combination with the at leastone ToF detector may solve the above-mentioned problem of thesensitivity of ToF detectors towards the nature of the object to bedetected or towards obstacles or media within the light path between thedetector and the object to be detected, such as the sensitivity towardsrain or weather conditions. A combined SLM/ToF measurement may be usedto extract the important information from ToF signals, or measurecomplex objects with several transparent or semi-transparent layers.Thus, objects made of glass, crystals, liquid structures, phasetransitions, liquid motions, etc. may be observed. Further, thecombination of an SLM detector and at least one ToF detector will stillwork in rainy weather, and the overall optical detector will generallybe less dependent from weather conditions. As an example, measurementresults provided by the SLM detector may be used to remove the errorsprovoked by rain from ToF measurement results, which specifically isrenders this combination useful for safety applications such as in carsor other vehicles.

The implementation of at least one ToF detector into the opticaldetector according to the present invention may be realized in variousways. Thus, the at least one SLM detector and the at least one ToFdetector may be arranged in a sequence, within the same light path. Asan example, at least one transparent SLM detector may be placed in frontof at least one ToF detector. Additionally or alternatively, separatelight paths or split light paths for the SLM detector and the ToFdetector may be used. Therein, as an example, light paths may beseparated by one or more beam-splitting elements, such as one or more ofthe beam splitting elements listed above listed in further detail below.As an example, a separation of beam paths by wavelength-selectiveelements may be performed. Thus, e.g., the ToF detector may make use ofinfrared light, whereas the SLM detector may make use of light of adifferent wavelength. In this example, the infrared light for the ToFdetector may be separated off by using a wavelength-selective beamsplitting element such as a hot mirror. Additionally or alternatively,light beams used for the SLM measurement and light beams used for theToF measurement may be separated by one or more beam-splitting elements,such as one or more semitransparent mirrors, beam-splitter cubes,polarization beam splitters or combinations thereof. Further, the atleast one SLM detector and the at least one ToF detector may be placednext to each other in the same device, using distinct optical pathways.Various other setups are feasible.

As outlined above, the optical detector according to the presentinvention as well as one or more of the other devices as proposed withinthe present invention may be combined with one or more other types ofmeasurement devices. Thus, the optical detector according to the presentinvention, comprising at least one spatial light modulator and at leastone optical sensor, may be combined with one or more other types ofsensors or detectors, such as the above-mentioned ToF detector. Whencombining the optical detector according to the present invention withone or more other types of sensors or detectors, the optical detectorand the at least one further sensor or detector may be designed asindependent devices, with the at least one optical sensor and thespatial light modulator of the optical detector being separate from theat least one further sensor or detector. Alternatively, one or more ofthese components may fully or partially be used for the further sensoror detector, too, or the optical sensor as well as the spatial lightmodulator and the at least one further sensor or detector may be fullyor partially combined in another way.

Thus, as a non-limiting example, the optical detector, as an example,may further comprise at least one distance sensor other than theabove-mentioned ToF detector, in addition or as alternatives to the atleast one optional ToF detector. The distance sensor, for instance, maybe based on the above-mentioned FiP-effect. Consequently, the opticaldetector may further comprise at least one active distance sensor. Asused herein, an “active distance sensor” is a sensor having at least oneactive optical sensor and at least one active illumination source,wherein the active distance sensor is adapted to determine a distancebetween an object and the active distance sensor. The active distancesensor comprises at least one active optical sensor adapted to generatea sensor signal when illuminated by a light beam propagating from theobject to the active optical sensor, wherein the sensor signal, giventhe same total power of the illumination, is dependent on a geometry ofthe illumination, in particular on a beam cross section of theillumination on the sensor area. The active distance sensor furthercomprises at least one active illumination source for illuminating theobject. Thus, the active illumination source may illuminate the object,and illumination light or a primary light beam generated by theillumination source may be reflected or scattered by the object or partsthereof, thereby generating a light beam propagating towards the opticalsensor of the active distance sensor.

For possible setups of the at least one active optical sensor of theactive distance sensor, reference may be made to one or more of WO2012/110924 A1 or WO2014/097181 A1, the full content of which isherewith included by reference. The at least one longitudinal opticalsensor disclosed in one or both of these documents may also be used forthe optional active distance sensor which may be included into theoptical detector according to the present invention. Thus, a singleoptical sensor may be used or a combination of a plurality of opticalsensors, such as a sensor stack.

As outlined above, the active distance sensor and the remainingcomponents of the optical detector may be separate components or maycome alternatively, fully or partially integrated. Consequently, the atleast one active optical sensor of the active distance sensor may fullyor partially be separate from the at least one optical sensor or mayfully or partially be identical to the at least one optical sensor ofthe optical detector. Similarly, the at least one active illuminationsource may fully or partially be separate from the illumination sourceof the optical detector or may fully or partially be identical.

The at least one active distance sensor may further comprise at leastone active evaluation device which may fully or partially be identicalto the evaluation device of the optical detector or which may be aseparate device. The at least one active evaluation device may beadapted to evaluate the at least one sensor signal of the at least oneactive optical sensor and to determine a distance between the object andthe active distance sensor. For this evaluation, a predetermined ordeterminable relationship between the at least one sensor signal and thedistance may be used, such as a predetermined relationship determined byempirical measurements and/or a predetermined relationship fully orpartially based on a theoretical dependency of the sensor signal on thedistance. For potential embodiments of this evaluation, reference may bemade to one or more of WO 2012/110924 A1 or WO2014/097181 A1, the fullcontent of which is herewith included by reference.

The at least one active illumination source may be a modulatedillumination source or a continuous illumination source. For potentialembodiments of this active illumination source, reference may be made tothe options disclosed above in the context of the illumination source.Specifically, the at least one active optical sensor may be adapted suchthat the sensor signal generated by this at least one active opticalsensor is dependent on a modulation frequency of the light beam.

The at least one active illumination source may illuminate the at leastone object in an on-axis fashion, such that the illumination sourcepropagates towards the object on an optical axis of the optical detectorand/or the active distance sensor. Additionally or alternatively, the atleast one illumination source may be adapted to illuminate the at leastone object in an off-axis fashion, such that the illumination lightpropagating towards the object and the light beam propagating from theobject to the active distance sensor are oriented in a nonparallelfashion.

The active illumination source may be a homogeneous illumination sourceor may be a patterned or structured illumination source. Thus, as anexample, the at least one active illumination source may be adapted toilluminate a scene or a part of a scene captured by the optical detectorwith homogeneous light and/or with patterned light. Thus, as an example,one or more light patterns may be projected into the scene and/or into apart of the scene, whereby a contrast of detection of the at least oneobject may be increased. As an example, line patterns or point patterns,such as rectangular line patterns and/or a rectangular matrix of lightpoints may be projected into the scene or into a part of the scene. Forgenerating light patterns, the at least one active illumination sourceby itself may be adapted to generate patterned light and/or one or morelight-patterning devices may be used, such as filters, gratings, mirrorsor other types of light-patterning devices. Further, additionally oralternatively, one or more light-patterning devices having a spatiallight modulator may be used. The spatial light modulator of the activedistance sensor may be separate and distinct from the above-mentionedspatial light modulator or may fully or partially be identical. Thus,for generating patterned light, micro-mirrors may be used, such as theabove-mentioned DLPs. Additionally or alternatively, other types ofpatterning devices may be used.

The combination of the optical detector having the optical sensor andthe spatial light modulator with the at least one optional activedistance sensor provides a plurality of advantages. Thus, a combinationwith a structured active distance sensor, such as an active distancesensor having at least one patterned or structured active illuminationsource, may render the overall system more reliable. As an example, whenthe above-mentioned principle of the optical detector, using the opticalsensor, the spatial light modulator and the modulation of the pixels,should fail to work properly, such as due to low contrast of the scenecaptured by the optical detector, the active distance sensor may beused. Contrarily, when the active distance sensor fails to workproperly, such as due to reflections of the at least one activeillumination source on transparent objects due to fog or rain, the basicprinciple of the optical detector using the spatial light modulator andthe modulation of pixels may still resolve objects with proper contrast.Consequently, as for the time-of-flight detector, the active distancesensor may improve reliability and stability of measurements generatedby the optical detector.

As outlined above, the optical detector may comprise one or morebeam-splitting elements adapted for splitting a beam path of the opticaldetector into two or more partial beam paths. Various types ofbeam-splitting elements may be used, such as prisms, gratings,semi-transparent mirrors, beam-splitter cubes, a reflective spatiallight modulator, or combinations thereof. Other possibilities arefeasible.

The beam-splitting element may be adapted to divide the light beam intoat least two portions having identical intensities or having differentintensities. In the latter case, the partial light beams and theirintensities may be adapted to their respective purposes. Thus, in eachof the partial beam paths, one or more optical elements, such as one ormore optical sensors may be located. By using at least onebeam-splitting element adapted for dividing the light beam into at leasttwo portions having different intensities, the intensities of thepartial light beams may be adapted to the specific requirements of theat least two optical sensors.

The beam-splitting element specifically may be adapted to divide thelight beam into a first portion traveling along a first partial beampath and at least one second portion traveling along at least one secondpartial beam path, wherein the first portion has a lower intensity thanthe second portion. The optical detector may contain at least oneimaging device, preferably an inorganic imaging device, more preferablya CCD chip and/or a CMOS chip. Since, typically, imaging devices requirelower light intensities as compared to other optical sensors, e.g. ascompared to the at least one longitudinal optical sensor, such as the atleast one FiP sensor, the at least one imaging device specifically maybe located in the first partial beam path. The first portion, as anexample, may have an intensity of lower than one half the intensity ofthe second portion. Other embodiments are feasible.

The intensities of the at least two portions may be adjusted in variousways, such as by adjusting a transmissivity and/or reflectivity of thebeam-splitting element, by adjusting a surface area of the beamsplitting-element or by other ways. The beam-splitting element generallymay be or may comprise a beam-splitting element which is indifferentregarding a potential polarization of the light beam. Still, however,the at least one beam-splitting element also may be or may comprise atleast one polarization-selective beam-splitting element. Various typesof polarization-selective beam-splitting elements are generally known inthe art. Thus, as an example, the polarization-selective beam-splittingelement may be or may comprise a polarization beam-splitting cube.Polarization-selective beam-splitting elements generally are favorablein that a ratio of the intensities of the partial light beams may beadjusted by adjusting a polarization of the light beam entering thepolarization-selective beam-splitting element.

The optical detector may be adapted to at least partially back-reflectone or more partial light beams traveling along the partial beam pathstowards the beam-splitting element. Thus, as an example, the opticaldetector may comprise one or more reflective elements adapted to atleast partially back-reflect a partial light beam towards thebeam-splitting element. The at least one reflective element may be ormay comprise at least one mirror. Additionally or alternatively, othertypes of reflective elements may be used, such as reflective prismsand/or the at least one spatial light modulator which, specifically, maybe a reflective spatial light modulator and which may be arranged to atleast partially back-reflect a partial light beam towards thebeam-splitting element. The beam-splitting element may be adapted to atleast partially recombine the back-reflected partial light beams inorder to form at least one common light beam. The optical detector maybe adapted to feed the re-united common light beam into at least oneoptical sensor, preferably into at least one longitudinal opticalsensor, specifically at least one FiP sensor, more preferably into astack of optical sensors such as a stack of FiP sensors.

The optical detector may comprise one or more spatial light modulators.In case a plurality of spatial light modulators is comprised, such astwo or more spatial light modulators, the at least two spatial lightmodulators may be arranged in the same beam path or may be arranged indifferent partial beam paths. In case the spatial light modulators arearranged in different beam paths, the optical detector, specifically theat least one beam-splitting element, may be adapted to recombine partiallight beams passing the spatial light modulators to form a common lightbeam.

In a further aspect of the present invention, a detector system fordetermining a position of at least one object is disclosed. The detectorsystem comprises at least one optical detector according to the presentinvention, such as according to one or more of the embodiments disclosedabove or disclosed in further detail below. The detector system furthercomprises at least one beacon device adapted to direct at least onelight beam towards the optical detector, wherein the beacon device is atleast one of attachable to the object, holdable by the object andintegratable into the object.

As used herein, a “detector system” generally refers to a device orarrangement of devices interacting to provide at least one detectorfunction, preferably at least one optical detector function, such as atleast one optical measurement function and/or at least one imagingoff-camera function. The detector system may comprise at least oneoptical detector, as outlined above, and may further comprise one ormore additional devices. The detector system may be integrated into asingle, unitary device or may be embodied as an arrangement of aplurality of devices interacting in order to provide the detectorfunction.

As outlined above, the detector system comprises at least one beacondevice adapted to direct at least one light beam towards the detector.As used herein and as will be disclosed in further detail below, a“beacon device” generally refers to an arbitrary device adapted todirect at least one light beam towards the detector. The beacon devicemay fully or partially be embodied as an active beacon device,comprising at least one illumination source for generating the lightbeam. Additionally or alternatively, the beacon device may fully orpartially be embodied as a passive beacon device comprising at least onereflective element adapted to reflect a primary light beam generatedindependently from the beacon device towards the detector.

The beacon device is at least one of attachable to the object, holdableby the object and integratable into the object. Thus, the beacon devicemay be attached to the object by an arbitrary attachment means, such asone or more connecting elements. Additionally or alternatively, theobject may be adapted to hold the beacon device, such as by one or moreappropriate holding means. Additionally or alternatively, again, thebeacon device may fully or partially be integrated into the object and,thus, may form part of the object or even may form the object.

Generally, with regard to potential embodiments of the beacon device,reference may be made to one or more of U.S. provisional applications61/739,173, filed on Dec. 19, 2012, and 61/749,964, filed on Jan. 8,2013, and/or to European patent application number EP 13171901.5. Still,other embodiments are feasible.

As outlined above, the beacon device may fully or partially be embodiedas an active beacon device and may comprise at least one illuminationsource. Thus, as an example, the beacon device may comprise a generallyarbitrary illumination source, such as an illumination source selectedfrom the group consisting of a light-emitting diode (LED), a light bulb,an incandescent lamp and a fluorescent lamp. Other embodiments arefeasible.

Additionally or alternatively, as outlined above, the beacon device mayfully or partially be embodied as a passive beacon device and maycomprise at least one reflective device adapted to reflect a primarylight beam generated by an illumination source independent from theobject. Thus, in addition or alternatively to generating the light beam,the beacon device may be adapted to reflect a primary light beam towardsthe detector.

In case an additional illumination source is used by the opticaldetector, the at least one illumination source may be part of theoptical detector. Additionally or alternatively, other types ofillumination sources may be used. The illumination source may be adaptedto fully or partially illuminate a scene. Further, the illuminationsource may be adapted to provide one or more primary light beams whichare fully or partially reflected by the at least one beacon device.Further, the illumination source may be adapted to provide one or moreprimary light beams which are fixed in space and/or to provide one ormore primary light beams which are movable, such as one or more primarylight beams which scan through a specific region in space. Thus, as anexample, one or more illumination sources may be provided which aremovable and/or which comprise one or more movable mirrors to adjust ormodify a position and/or orientation of the at least one primary lightbeam in space, such as by scanning the at least one primary light beamthrough a specific scene captured by the optical detector. In case oneor more movable mirrors are used, the movable mirror may also compriseone or more spatial light modulators, such as one or more micro-mirrors,specifically one or more of the micro-mirrors based on DLP® technology,as disclosed above. Thus, as an example, a scene may be illuminated byusing at least one first spatial light modulator, and the actualmeasurement via the optical detector may be performed by using at leastone second spatial light modulator.

The detector system may comprise one, two, three or more beacon devices.Thus, generally, in case the object is a rigid object which, at least ona microscope scale, does not change its shape, preferably, at least twobeacon devices may be used. In case the object is fully or partiallyflexible or is adapted to fully or partially change its shape,preferably, three or more beacon devices may be used. Generally, thenumber of beacon devices may be adapted to the degree of flexibility ofthe object. Preferably, the detector system comprises at least threebeacon devices.

The object itself may be part of the detector system or may beindependent from the detector system. Thus, generally, the detectorsystem may further comprise the at least one object. One or more objectsmay be used. The object may be a rigid object and/or a flexible object.

The object generally may be a living or non-living object. The detectorsystem even may comprise the at least one object, the object therebyforming part of the detector system. Preferably, however, the object maymove independently from the detector, in at least one spatial dimension.

The object generally may be an arbitrary object. In one embodiment, theobject may be a rigid object. Other embodiments are feasible, such asembodiments in which the object is a non-rigid object or an object whichmay change its shape.

As will be outlined in further detail below, the present invention mayspecifically be used for tracking positions and/or motions of a person,such as for the purpose of controlling machines, gaming or simulation ofsports. In this or other embodiments, specifically, the object may beselected from the group consisting of: an article of sports equipment,preferably an article selected from the group consisting of a racket, aclub, a bat; an article of clothing; a hat; a shoe.

The optional transfer device can, as explained above, be designed tofeed light propagating from the object to the optical detector. Asexplained above, this feeding can optionally be effected by means ofimaging or else by means of non-imaging properties of the transferdevice. In particular the transfer device can also be designed tocollect the electromagnetic radiation before the latter is fed to thespatial light modulator and/or the optical sensor. The optional transferdevice can also be wholly or partly a constituent part of at least oneoptional illumination source, for example by the illumination sourcebeing designed to provide a light beam having defined opticalproperties, for example having a defined or precisely known beamprofile, for example at least one Gaussian beam, in particular at leastone laser beam having a known beam profile.

For potential embodiments of the optional illumination source, referencemay be made to WO 2012/110924 A1. Still, other embodiments are feasible.Light emerging from the object can originate in the object itself, butcan also optionally have a different origin and propagate from thisorigin to the object and subsequently toward the spatial light modulatorand/or the optical sensor. The latter case can be effected for exampleby at least one illumination source being used. This illumination sourcecan for example be or comprise an ambient illumination source and/or maybe or may comprise an artificial illumination source. By way of example,the detector itself can comprise at least one illumination source, forexample at least one laser and/or at least one incandescent lamp and/orat least one semiconductor illumination source, for example, at leastone light-emitting diode, in particular an organic and/or inorganiclight-emitting diode. On account of their generally defined beamprofiles and other properties of handleability, the use of one or aplurality of lasers as illumination source or as part thereof, isparticularly preferred. The illumination source itself can be aconstituent part of the detector or else be formed independently of theoptical detector. The illumination source can be integrated inparticular into the optical detector, for example a housing of thedetector. Alternatively or additionally, at least one illuminationsource can also be integrated into the at least one beacon device orinto one or more of the beacon devices and/or into the object orconnected or spatially coupled to the object.

The light emerging from the one or more beacon devices can accordingly,alternatively or additionally from the option that said light originatesin the respective beacon device itself, emerge from the illuminationsource and/or be excited by the illumination source. By way of example,the electromagnetic light emerging from the beacon device can be emittedby the beacon device itself and/or be reflected by the beacon deviceand/or be scattered by the beacon device before it is fed to thedetector. In this case, emission and/or scattering of theelectromagnetic radiation can be effected without spectral influencingof the electromagnetic radiation or with such influencing. Thus, by wayof example, a wavelength shift can also occur during scattering, forexample according to Stokes or Raman. Furthermore, emission of light canbe excited, for example, by a primary illumination source, for exampleby the object or a partial region of the object being excited togenerate luminescence, in particular phosphorescence and/orfluorescence. Other emission processes are also possible, in principle.If a reflection occurs, then the object can have for example at leastone reflective region, in particular at least one reflective surface.Said reflective surface can be a part of the object itself, but can alsobe for example a reflector which is connected or spatially coupled tothe object, for example a reflector plaque connected to the object. Ifat least one reflector is used, then it can in turn also be regarded aspart of the detector which is connected to the object, for example,independently of other constituent parts of the optical detector.

The beacon devices and/or the at least one optional illumination sourceindependently from each other and generally may emit light in at leastone of: the ultraviolet spectral range, preferably in the range of 200nm to 380 nm; the visible spectral range (380 nm to 780 nm); theinfrared spectral range, preferably in the range of 780 nm to 3.0micrometers. Most preferably, the at least one illumination source isadapted to emit light in the visible spectral range, preferably in therange of 500 nm to 780 nm, most preferably at 650 nm to 750 nm or at 690nm to 700 nm.

The feeding of the light beam to the optical sensor can be effected inparticular in such a way that a light spot, for example having a round,oval or differently configured cross section, is produced on theoptional sensor area of the optical sensor. By way of example, thedetector can have a visual range, in particular a solid angle rangeand/or spatial range, within which objects can be detected. Preferably,the optional transfer device is designed in such a way that the lightspot, for example in the case of an object arranged within a visualrange of the detector, is arranged completely on a sensor region and/oron a sensor area of the optical sensor. By way of example, a sensor areacan be chosen to have a corresponding size in order to ensure thiscondition.

The evaluation device can comprise in particular at least one dataprocessing device, in particular an electronic data processing device,which can be designed to generate at least one item of information onthe position of the object. Thus, the evaluation device may be designedto use one or more of: the number of illuminated pixels of the spatiallight modulator; a beam width of the light beam on one or more of theoptical sensors, specifically on one or more of the optical sensorshaving the above-mentioned FiP-effect; a number of illuminated pixels ofa pixelated optical sensor such as a CCD or a CMOS chip. The evaluationdevice may be designed to use one or more of these types of informationas one or more input variables and to generate the at least one item ofinformation on the position of the object by processing these inputvariables. The processing can be done in parallel, subsequently or evenin a combined manner. The evaluation device may use an arbitrary processfor generating these items of information, such as by calculation and/orusing at least one stored and/or known relationship. The relationshipcan be a predetermined analytical relationship or can be determined ordeterminable empirically, analytically or else semi-empirically.Particularly preferably, the relationship comprises at least onecalibration curve, at least one set of calibration curves, at least onefunction or a combination of the possibilities mentioned. One or aplurality of calibration curves can be stored for example in the form ofa set of values and the associated function values thereof, for examplein a data storage device and/or a table. Alternatively or additionally,however, the at least one calibration curve can also be stored forexample in parameterized form and/or as a functional equation.

By way of example, the evaluation device can be designed in terms ofprogramming for the purpose of determining the items of information. Theevaluation device can comprise in particular at least one computer, forexample at least one microcomputer. Furthermore, the evaluation devicecan comprise one or a plurality of volatile or nonvolatile datamemories. As an alternative or in addition to a data processing device,in particular at least one computer, the evaluation device can compriseone or a plurality of further electronic components which are designedfor determining the items of information, for example an electronictable and in particular at least one look-up table and/or at least oneapplication-specific integrated circuit (ASIC).

In a further aspect of the present invention, a human-machine interfacefor exchanging at least one item of information between a user and amachine is disclosed. The human-machine interface comprises at least onedetector system according to the present invention, such as according toone or more of the embodiments disclosed above or disclosed in furtherdetail below. The at least one beacon device of the detector system isadapted to be at least one of directly or indirectly attached to theuser and held by the user. The human-machine interface is designed todetermine at least one position of the user by means of the detectorsystem and is designed to assign to the position at least one item ofinformation.

As used herein, the term “human-machine interface” generally refers toan arbitrary device or combination of devices adapted for exchanging atleast one item of information, specifically at least one item ofelectronic information, between a user and a machine such as a machinehaving at least one data processing device. The exchange of informationmay be performed in a unidirectional fashion and/or in a bidirectionalfashion. Specifically, the human-machine interface may be adapted toallow for a user to provide one or more commands to the machine in amachine-readable fashion.

In a further aspect of the invention, an entertainment device forcarrying out at least one entertainment function is disclosed. Theentertainment device comprises at least one human-machine interfaceaccording to the present invention, such as disclosed in one or more ofthe embodiments disclosed above or disclosed in further detail below.The entertainment device is designed to enable at least one item ofinformation to be input by a player by means of the human-machineinterface, wherein the entertainment device is designed to vary theentertainment function in accordance with the information.

As used herein, an “entertainment device” is a device which may servethe purpose of leisure and/or entertainment of one or more users, in thefollowing also referred to as one or more players. As an example, theentertainment device may serve the purpose of gaming, preferablycomputer gaming. Additionally or alternatively, the entertainment devicemay also be used for other purposes, such as for exercising, sports,physical therapy or motion tracking in general. Thus, the entertainmentdevice may be implemented into a computer, a computer network or acomputer system or may comprise a computer, a computer network or acomputer system which runs one or more gaming software programs.

The entertainment device comprises at least one human-machine interfaceaccording to the present invention, such as according to one or more ofthe embodiments disclosed above and/or according to one or more of theembodiments disclosed below. The entertainment device is designed toenable at least one item of information to be input by a player by meansof the human-machine interface. The at least one item of information maybe transmitted to and/or may be used by a controller and/or a computerof the entertainment device.

The at least one item of information preferably may comprise at leastone command adapted for influencing the course of a game. Thus, as anexample, the at least one item of information may include at least oneitem of information on at least one orientation of the player and/or ofone or more body parts of the player, thereby allowing for the player tosimulate a specific position and/or orientation and/or action requiredfor gaming. As an example, one or more of the following movements may besimulated and communicated to a controller and/or a computer of theentertainment device: dancing; running; jumping; swinging of a racket;swinging of a bat; swinging of a club; pointing of an object towardsanother object, such as pointing of a toy gun towards a target.

The entertainment device as a part or as a whole, preferably acontroller and/or a computer of the entertainment device, is designed tovary the entertainment function in accordance with the information.Thus, as outlined above, a course of a game might be influenced inaccordance with the at least one item of information. Thus, theentertainment device might include one or more controllers which mightbe separate from the evaluation device of the at least one detectorand/or which might be fully or partially identical to the at least oneevaluation device or which might even include the at least oneevaluation device. Preferably, the at least one controller might includeone or more data processing devices, such as one or more computersand/or microcontrollers.

In a further aspect of the present invention, a tracking system fortracking a position of at least one movable object is disclosed. Thetracking system comprises at least one detector system according to thepresent invention, such as disclosed in one or more of the embodimentsgiven above or given in further detail below. The tracking systemfurther comprises at least one track controller, wherein the trackcontroller is adapted to track a series of positions of the object atspecific points in time.

As used herein, a “tracking system” is a device which is adapted togather information on a series of past positions of the at least oneobject and/or at least one part of the object. Additionally, thetracking system may be adapted to provide information on at least onepredicted future position and/or orientation of the at least one objector the at least one part of the object. The tracking system may have atleast one track controller, which may fully or partially be embodied asan electronic device, preferably as at least one data processing device,more preferably as at least one computer or microcontroller. Again, theat least one track controller may fully or partially comprise the atleast one evaluation device and/or may be part of the at least oneevaluation device and/or may fully or partially be identical to the atleast one evaluation device.

The tracking system comprises at least one detector according to thepresent invention, such as at least one detector as disclosed in one ormore of the embodiments listed above and/or as disclosed in one or moreof the embodiments below. The tracking system further comprises at leastone track controller. The track controller is adapted to track a seriesof positions of the object at specific points in time, such as byrecording groups of data or data pairs, each group of data or data paircomprising at least one position information and at least one timeinformation.

The tracking system may further comprise the at least one detectorsystem according to the present invention. Thus, besides the at leastone detector and the at least one evaluation device and the optional atleast one beacon device, the tracking system may further comprise theobject itself or a part of the object, such as at least one controlelement comprising the beacon devices or at least one beacon device,wherein the control element is directly or indirectly attachable to orintegratable into the object to be tracked.

The tracking system may be adapted to initiate one or more actions ofthe tracking system itself and/or of one or more separate devices. Forthe latter purpose, the tracking system, preferably the trackcontroller, may have one or more wireless and/or wire-bound interfacesand/or other types of control connections for initiating at least oneaction. Preferably, the at least one track controller may be adapted toinitiate at least one action in accordance with at least one actualposition of the object. As an example, the action may be selected fromthe group consisting of: a prediction of a future position of theobject; pointing at least one device towards the object; pointing atleast one device towards the detector; illuminating the object;illuminating the detector.

As an example of application of a tracking system, the tracking systemmay be used for continuously pointing at least one first object to atleast one second object even though the first object and/or the secondobject might move. Potential examples, again, may be found in industrialapplications, such as in robotics and/or for continuously working on anarticle even though the article is moving, such as during manufacturingin a manufacturing line or assembly line. Additionally or alternatively,the tracking system might be used for illumination purposes, such as forcontinuously illuminating the object by continuously pointing anillumination source to the object even though the object might bemoving. Further applications might be found in communication systems,such as in order to continuously transmit information to a moving objectby pointing a transmitter towards the moving object.

In a further aspect of the present invention, a scanning system fordetermining at least one position of at least one object is provided. Asused herein, the scanning system is a device which is adapted to emit atleast one light beam being configured for an illumination of at leastone dot located at at least one surface of the at least one object andfor generating at least one item of information about the distancebetween the at least one dot and the scanning system. For the purpose ofgenerating the at least one item of information about the distancebetween the at least one dot and the scanning system, the scanningsystem comprises at least one of the detectors according to the presentinvention, such as at least one of the detectors as disclosed in one ormore of the embodiments listed above and/or as disclosed in one or moreof the embodiments below.

Thus, the scanning system comprises at least one illumination sourcewhich is adapted to emit the at least one light beam being configuredfor the illumination of the at least one dot located at the at least onesurface of the at least one object. As used herein, the term “dot”refers to an area, specifically a small area, on a part of the surfaceof the object which may be selected, for example by a user of thescanning system, to be illuminated by the illumination source.Preferably, the dot may exhibit a size which may, on one hand, be assmall as possible in order to allow the scanning system determining avalue for the distance between the illumination source comprised by thescanning system and the part of the surface of the object on which thedot may be located as exactly as possible and which, on the other hand,may be as large as possible in order to allow the user of the scanningsystem or the scanning system itself, in particular by an automaticprocedure, to detect a presence of the dot on the related part of thesurface of the object.

For this purpose, the illumination source may comprise an artificialillumination source, in particular at least one laser source and/or atleast one incandescent lamp and/or at least one semiconductor lightsource, for example, at least one light-emitting diode, in particular anorganic and/or inorganic light-emitting diode. On account of theirgenerally defined beam profiles and other properties of handleability,the use of at least one laser source as the illumination source isparticularly preferred. Herein, the use of a single laser source may bepreferred, in particular in a case in which it may be important toprovide a compact scanning system that might be easily storable andtransportable by the user. The illumination source may thus, preferablybe a constituent part of the detector and may, therefore, in particularbe integrated into the detector, such as into the housing of thedetector. In a preferred embodiment, particularly the housing of thescanning system may comprise at least one display configured forproviding distance-related information to the user, such as in aneasy-to-read manner. In a further preferred embodiment, particularly thehousing of the scanning system may, in addition, comprise at least onebutton which may be configured for operating at least one functionrelated to the scanning system, such as for setting one or moreoperation modes. In a further preferred embodiment, particularly thehousing of the scanning system may, in addition, comprise at least onefastening unit which may be configured for fastening the scanning systemto a further surface, such as a rubber foot, a base plate or a wallholder, such comprising as magnetic material, in particular forincreasing the accuracy of the distance measurement and/or thehandleability of the scanning system by the user.

In a particularly preferred embodiment, the illumination source of thescanning system may, thus, emit a single laser beam which may beconfigured for the illumination of a single dot located at the surfaceof the object. By using at least one of the detectors according to thepresent invention at least one item of information about the distancebetween the at least one dot and the scanning system may, thus, begenerated. Hereby, preferably, the distance between the illuminationsystem as comprised by the scanning system and the single dot asgenerated by the illumination source may be determined, such as byemploying the evaluation device as comprised by the at least onedetector. However, the scanning system may, further, comprise anadditional evaluation system which may, particularly, be adapted forthis purpose. Alternatively or in addition, a size of the scanningsystem, in particular of the housing of the scanning system, may betaken into account and, thus, the distance between a specific point onthe housing of the scanning system, such as a front edge or a back edgeof the housing, and the single dot may, alternatively, be determined.

Alternatively, the illumination source of the scanning system may emittwo individual laser beams which may be configured for providing arespective angle, such as a right angle, between the directions of anemission of the beams, whereby two respective dots located at thesurface of the same object or at two different surfaces at two separateobjects may be illuminated. However, other values for the respectiveangle between the two individual laser beams may also be feasible. Thisfeature may, in particular, be employed for indirect measuringfunctions, such as for deriving an indirect distance which may not bedirectly accessible, such as due to a presence of one or more obstaclesbetween the scanning system and the dot or which may otherwise be hardto reach. By way of example, it may, thus, be feasible to determine avalue for a height of an object by measuring two individual distancesand deriving the height by using the Pythagoras formula. In particularfor being able to keep a predefined level with respect to the object,the scanning system may, further, comprise at least one leveling unit,in particular an integrated bubble vial, which may be used for keepingthe predefined level by the user.

As a further alternative, the illumination source of the scanning systemmay emit a plurality of individual laser beams, such as an array oflaser beams which may exhibit a respective pitch, in particular aregular pitch, with respect to each other and which may be arranged in amanner in order to generate an array of dots located on the at least onesurface of the at least one object. For this purpose, specially adaptedoptical elements, such as beam-splitting devices and mirrors, may beprovided which may allow a generation of the described array of thelaser beams. In particular, the illumination source may be directed toscan an area or a volume by using one or more movable mirrors toredirect the light beam in a periodic or non-periodic fashion. Theillumination source may further be redirected using an array ofmicro-mirrors in order to provide in this manner a structured lightsource. The structured light source may be used to project opticalfeatures, such as points or fringes.

Thus, the scanning system may provide a static arrangement of the one ormore dots placed on the one or more surfaces of the one or more objects.Alternatively, the illumination source of the scanning system, inparticular the one or more laser beams, such as the above describedarray of the laser beams, may be configured for providing one or morelight beams which may exhibit a varying intensity over time and/or whichmay be subject to an alternating direction of emission in a passage oftime, in particular by moving one or more mirrors, such as themicro-mirrors comprised within the mentioned array of micro-mirrors. Asa result, the illumination source may be configured for scanning a partof the at least one surface of the at least one object as an image byusing one or more light beams with alternating features as generated bythe at least one illumination source of the scanning device. Inparticular, the scanning system may, thus, use at least one row scanand/or line scan, such as to scan the one or more surfaces of the one ormore objects sequentially or simultaneously. As non-limiting examples,the scanning system may be used in safety laser scanners, e.g. inproduction environments, and/or in 3D-scanning devices as used fordetermining the shape of an object, such as in connection to3D-printing, body scanning, quality control, in constructionapplications, e.g. as range meters, in logistics applications, e.g. fordetermining the size or volume of a parcel, in household applications,e.g. in robotic vacuum cleaners or lawn mowers, or in other kinds ofapplications which may include a scanning step.

In a further aspect of the present invention, a camera for imaging atleast one object is disclosed. The camera comprises at least one opticaldetector according to the present invention, such as disclosed in one ormore of the embodiments given above or given in further detail below.

Thus, specifically, the present application may be applied in the fieldof photography. Thus, the detector may be part of a photographic device,specifically of a digital camera. Specifically, the detector may be usedfor 3D photography, specifically for digital 3D photography. Thus, thedetector may form a digital 3D camera or may be part of a digital 3Dcamera. As used herein, the term “photography” generally refers to thetechnology of acquiring image information of at least one object. Asfurther used herein, a “camera” generally is a device adapted forperforming photography. As further used herein, the term “digitalphotography” generally refers to the technology of acquiring imageinformation of at least one object by using a plurality oflight-sensitive elements adapted to generate electrical signalsindicating an intensity and/or color of illumination, preferably digitalelectrical signals. As further used herein, the term “3D photography”generally refers to the technology of acquiring image information of atleast one object in three spatial dimensions. Accordingly, a 3D camerais a device adapted for performing 3D photography. The camera generallymay be adapted for acquiring a single image, such as a single 3D image,or may be adapted for acquiring a plurality of images, such as asequence of images. Thus, the camera may also be a video camera adaptedfor video applications, such as for acquiring digital video sequences.

Thus, generally, the present invention further refers to a camera,specifically a digital camera, more specifically a 3D camera or digital3D camera, for imaging at least one object. As outlined above, the termimaging, as used herein, generally refers to acquiring image informationof at least one object. The camera comprises at least one opticaldetector according to the present invention. The camera, as outlinedabove, may be adapted for acquiring a single image or for acquiring aplurality of images, such as image sequence, preferably for acquiringdigital video sequences. Thus, as an example, the camera may be or maycomprise a video camera. In the latter case, the camera preferablycomprises a data memory for storing the image sequence. The opticaldetector or the camera including the optical detector, having the atleast one optical sensor, specifically the above-mentioned FiP sensor,may further be combined with one or more additional sensors. Thus, atleast one camera having the at least one optical sensor, specificallythe at least one above-mentioned FiP sensor, may be combined with atleast one further camera, which may be a conventional camera and/or e.g.a stereo camera. Further, one, two or more cameras having the at leastone optical sensor, specifically the at least one above-mentioned FiPsensor, may be combined with one, two or more digital cameras. As anexample, one or two or more two-dimensional digital cameras may be usedfor calculating the depth from stereo information and from the depthinformation gained by the optical detector according to the presentinvention.

Specifically in the field of automotive technology, in case a camerafails, the optical detector according to the present invention may stillbe present for measuring a longitudinal coordinate of an object, such asfor measuring a distance of an object in the field of view. Thus, byusing the optical detector according to the present invention in thefield of automotive technology, a failsafe function may be implemented.Specifically for automotive applications, the optical detector accordingto the present invention provides the advantage of data reduction. Thus,as compared to camera data of conventional digital cameras, dataobtained by using the optical detector according to the presentinvention, i.e. an optical detector having the at least one opticalsensor, specifically the at least one FiP sensor, may provide datahaving a significantly lower volume. Specifically in the field ofautomotive technology, a reduced amount of data is favorable, sinceautomotive data networks generally provide lower capabilities in termsof data transmission rate.

The optical detector according to the present invention may furthercomprise one or more light sources. Thus, the optical detector maycomprise one or more light sources for illuminating the at least oneobject, such that e.g. illuminated light is reflected by the object. Thelight source may be a continuous light source or maybe discontinuouslyemitting light source such as a pulsed light source. The light sourcemay be a uniform light source or may be a nonuniform light source or apatterned light source. Thus, as an example, in order for the opticaldetector to measure the at least one longitudinal coordinate, such as tomeasure the depth of at least one object, a contrast in the illuminationor in the scene captured by the optical detector is advantageous. Incase no contrast is present by natural illumination, the opticaldetector may be adapted, via the at least one optional light source, tofully or partially illuminate the scene and/or at least one objectwithin the scene, preferably with patterned light. Thus, as an example,the light source may project a pattern into a scene, onto a wall or ontoat least one object, in order to create an increased contrast within animage captured by the optical detector.

The at least one optional light source may generally emit light in oneor more of the visible spectral range, the infrared spectral range orthe ultraviolet spectral range. Preferably, the at least one lightsource emits light at least in the infrared spectral range.

The optical detector may also be adapted to automatically illuminate thescene. Thus, the optical detector, such as the evaluation device, may beadapted to automatically control the illumination of the scene capturedby the optical detector or a part thereof. Thus, as an example, theoptical detector may be adapted to recognize in case large areas providelow contrast, thereby making it difficult to measure the longitudinalcoordinates, such as depth, within these areas. In these cases, as anexample, the optical detector may be adapted to automatically illuminatethese areas with patterned light, such as by projecting one or morepatterns into these areas.

As used within the present invention, the expression “position”generally refers to at least one item of information regarding one ormore of an absolute position and an orientation of one or more points ofthe object. Thus, specifically, the position may be determined in acoordinate system of the detector, such as in a Cartesian coordinatesystem. Additionally or alternatively, however, other types ofcoordinate systems may be used, such as polar coordinate systems and/orspherical coordinate systems.

As outlined above, the at least one spatial light modulator of theoptical detector specifically may be or may comprise at least onereflective spatial light modulator such as a DLP. In case one or morereflective spatial light modulators are used, the optical detector mayfurther be adapted to use this at least one reflective spatial lightmodulator for more than the above-mentioned purposes. Thus,specifically, the optical detector may be adapted for additionally usingthe at least one spatial light modulator, specifically the at least onereflective spatial light modulator, for projecting light into space,such as into a scene and/or onto a screen. Thus, the detectorspecifically may be adapted to additionally provide at least oneprojector function.

Thus, as an example, DLP technology was mainly developed for projectors,such as projectors in communication devices like mobile phones. Thereby,an integrated projector may be implemented into a wide variety ofdevices. In the present invention, the spatial light modulatorspecifically may be used for distance sensing and/or for determining atleast one longitudinal coordinate of an object. These two functions,however, may be combined. Thus, a combination of a projector and adistance sensor in one device may be achieved.

This is due to the fact that the spatial light modulator, specificallythe reflective spatial light modulator, in combination with theevaluation device, may fulfill both the task of distance sensing ordetermining at least one longitudinal coordinate of an object and thetask of a projector, such as for projecting at least one image intospace, into a scene or onto a screen. The at least one spatial lightmodulator, to fulfill both tasks, specifically may be modulatedintermittently, such as by using modulation periods for distance sensingand modulation periods for projecting intermittently. Thus, reflectivespatial light modulators such as DLPs are generally capable of beingmodulated at modulation frequencies of more than I kHz. Consequently,realtime video frequencies may be reached for projections and fordistance measurements simultaneously with a single spatial lightmodulator such as a DLP. This allows, for example to use a mobile phoneto record a 3D-scene and to project it at the same time.

In a further aspect of the present invention, a use of the opticaldetector according to the present invention, such as disclosed in one ormore of the embodiments discussed above and/or as disclosed in one ormore of the embodiments given in further detail below, is disclosed, fora purpose of use, selected from the group consisting of: a positionmeasurement in traffic technology; an entertainment application; asecurity application; a human-machine interface application; a trackingapplication; a photography application; a mapping application forgenerating maps of at least one space, such as at least one spaceselected from the group of a room, a building and a street; a mobileapplication; a webcam; a computer peripheral device; a gamingapplication; a camera or video application; a security application; asurveillance application; an automotive application; a transportapplication; a medical application; a sports application; a machinevision application; a vehicle application; an airplane application; aship application; a spacecraft application; a building application; aconstruction application; a cartography application; a manufacturingapplication; a use in combination with at least one time-of-flightdetector. Additionally or alternatively, applications in local and/orglobal positioning systems may be named, especially landmark-basedpositioning and/or indoor and/or outdoor navigation, specifically foruse in cars or other vehicles (such as trains, motorcycles, bicycles,trucks for cargo transportation), robots or for use by pedestrians.Further, indoor positioning systems may be named as potentialapplications, such as for household applications and/or for robots usedin manufacturing technology. Further, the optical detector according tothe present invention may be used in automatic door openers, such as inso-called smart sliding doors, such as a smart sliding door disclosed inJie-Ci Yang et al., Sensors 2013, 13(5), 5923-5936;doi:10.3390/s130505923. At least one optical detector according to thepresent invention may be used for detecting when a person or an objectapproaches the door, and the door may automatically open.

Further applications, as outlined above, may be global positioningsystems, local positioning systems, indoor navigation systems or thelike. Thus, the devices according to the present invention, i.e. one ormore of the optical detector, the detector system, the human-machineinterface, the entertainment device, the tracking system or the camera,specifically may be part of a local or global positioning system.Additionally or alternatively, the devices may be part of a visiblelight communication system. Other uses are feasible.

The devices according to the present invention, i.e. one or more of theoptical detector, the detector system, the human-machine interface, theentertainment device, the tracking system or the camera, furtherspecifically may be used in combination with a local or globalpositioning system, such as for indoor or outdoor navigation. As anexample, one or more devices according to the present invention may becombined with software/database-combinations such as Google Maps® orGoogle Street View®. Devices according to the present invention mayfurther be used to analyze the distance to objects in the surrounding,the position of which can be found in the database. From the distance tothe position of the known object, the local or global position of theuser may be calculated.

Thus, as for the optical detectors and devices disclosed in WO2012/110924 A1 or in U.S. provisional applications 61/739,173, filed onDec. 19, 2012, and 61/749,964, filed on Jan. 8, 2013, the opticaldetector, the detector system, the human-machine interface, theentertainment device, the tracking system or the camera according to thepresent invention (in the following simply referred to as “the devicesaccording to the present invention” or—without restricting the presentinvention to the potential use of the FiP effect—“FiP-devices”) may beused for a plurality of application purposes, such as one or more of thepurposes disclosed in further detail in the following.

Thus, firstly, FiP-devices may be used in mobile phones, tabletcomputers, laptops, smart panels or other stationary or mobile computeror communication applications. Thus, FiP-devices may be combined with atleast one active light source, such as a light source emitting light inthe visible range or infrared spectral range, in order to enhanceperformance. Thus, as an example, FiP-devices may be used as camerasand/or sensors, such as in combination with mobile software for scanningenvironment, objects and living beings. FiP-devices may even be combinedwith 2D cameras, such as conventional cameras, in order to increaseimaging effects. FiP-devices may further be used for surveillance and/orfor recording purposes or as input devices to control mobile devices,especially in combination with gesture recognition. Thus, specifically,FiP-devices acting as human-machine interfaces, also referred to as FiPinput devices, may be used in mobile applications, such as forcontrolling other electronic devices or components via the mobiledevice, such as the mobile phone. As an example, the mobile applicationincluding at least one FiP-device may be used for controlling atelevision set, a game console, a music player or music device or otherentertainment devices.

Further, FiP-devices may be used in webcams or other peripheral devicesfor computing applications. Thus, as an example, FiP-devices may be usedin combination with software for imaging, recording, surveillance,scanning or motion detection. As outlined in the context of thehuman-machine interface and/or the entertainment device, FiP-devices areparticularly useful for giving commands by facial expressions and/orbody expressions. FiP-devices can be combined with other inputgenerating devices like e.g. mouse, keyboard, touchpad, etc. Further,FiP-devices may be used in applications for gaming, such as by using awebcam. Further, FiP-devices may be used in virtual trainingapplications and/or video conferences

Further, FiP-devices may be used in mobile audio devices, televisiondevices and gaming devices, as partially explained above. Specifically,FiP-devices may be used as controls or control devices for electronicdevices, entertainment devices or the like. Further, FiP-devices may beused for eye detection or eye tracking, such as in 2D- and 3D-displaytechniques, especially with transparent displays for augmented realityapplications.

Further, FiP-devices may be used in or as digital cameras such as DSCcameras and/or in or as reflex cameras such as SLR cameras. For theseapplications, reference may be made to the use of FiP-devices in mobileapplications such as mobile phones, as disclosed above.

Further, FiP-devices may be used for security and surveillanceapplications. Thus, as an example, FiP-sensors in general and,specifically, the present SLM-based optical detector, can be combinedwith one or more digital and/or analog electronics that will give asignal if an object is within or outside a predetermined area (e.g. forsurveillance applications in banks or museums). Specifically,FiP-devices may be used for optical encryption. FiP-based detection canbe combined with other detection devices to complement wavelengths, suchas with IR, x-ray, UV-VIS, radar or ultrasound detectors. FiP-devicesmay further be combined with an active infrared light source to allowdetection in low light surroundings. FiP-devices such as FIR-basedsensors are generally advantageous as compared to active detectorsystems, specifically since FiP-devices avoid actively sending signalswhich may be detected by third parties, as is the case e.g. in radarapplications, ultrasound applications, LIDAR or similar active detectordevice is. Thus, generally, FiP-devices may be used for an unrecognizedand undetectable tracking of moving objects. Additionally, FiP-devicesgenerally are less prone to manipulations and irritations as compared toconventional devices.

Further, given the ease and accuracy of 3D detection by usingFiP-devices, FiP-devices generally may be used for facial, body andperson recognition and identification. Therein, FiP-devices may becombined with other detection means for identification orpersonalization purposes such as passwords, finger prints, irisdetection, voice recognition or other means. Thus, generally,FiP-devices may be used in security devices and other personalizedapplications.

Further, FiP-devices may be used as 3D-Barcode readers for productidentification.

In addition to the security and surveillance applications mentionedabove, FiP-devices generally can be used for surveillance and monitoringof spaces and areas. Thus, FiP-devices may be used for surveying andmonitoring spaces and areas and, as an example, for triggering orexecuting alarms in case prohibited areas are violated. Thus, generally,HP-devices may be used for surveillance purposes in buildingsurveillance or museums, optionally in combination with other types ofsensors, such as in combination with motion or heat sensors, incombination with image intensifiers or image enhancement devices and/orphotomultipliers.

Further, FiP-devices may advantageously be applied in cameraapplications such as video and camcorder applications. Thus, FiP-devicesmay be used for motion capture and 3D-movie recording. Therein,FiP-devices generally provide a large number of advantages overconventional optical devices. Thus, FiP-devices generally require alower complexity with regard to optical components. Thus, as an example,the number of lenses may be reduced as compared to conventional opticaldevices, such as by providing FiP-devices having one lens only. Due tothe reduced complexity, very compact devices are possible, such as formobile use. Conventional optical systems having two or more lenses withhigh quality generally are voluminous, such as due to the general needfor voluminous beam-splitters. Further, FiP-devices generally may beused for focus/autofocus devices, such as autofocus cameras. Further,FiP-devices may also be used in optical microscopy, especially inconfocal microscopy. Further, FiP-devices generally are applicable inthe technical field of automotive technology and transport technology.Thus, as an example, FiP-devices may be used as distance andsurveillance sensors, such as for adaptive cruise control, emergencybrake assist, lane departure warning, surround view, blind spotdetection, rear cross traffic alert, and other automotive and trafficapplications. Further, FiP-sensors in general and, more specifically,the present SLM-based optical detector, can also be used for velocityand/or acceleration measurements, such as by analyzing a first andsecond time-derivative of position information gained by using theFiP-sensor. This feature generally may be applicable in automotivetechnology, transportation technology or general traffic technology.Applications in other fields of technology are feasible.

In these or other applications, generally, FiP-devices may be used asstandalone devices or in combination with other sensor devices, such asin combination with radar and/or ultrasonic devices. Specifically,FiP-devices may be used for autonomous driving and safety issues.Further, in these applications, FiP-devices may be used in combinationwith infrared sensors, radar sensors, which are sonic sensors,two-dimensional cameras or other types of sensors. In theseapplications, the generally passive nature of typical FiP-devices isadvantageous. Thus, since FiP-devices generally do not require emittingsignals, the risk of interference of active sensor signals with othersignal sources may be avoided. FiP-devices specifically may be used incombination with recognition software, such as standard imagerecognition software. Thus, signals and data as provide by FiP-devicestypically are readily processable and, therefore, generally requirelower calculation power than established stereovision systems such asLIDAR. Given the low space demand, FiP-devices such as cameras using theFiP-effect may be placed at virtually any place in a vehicle, such as ona window screen, on a front hood, on bumpers, on lights, on mirrors orother places the like. Various detectors based on the FiP-effect can becombined, such as in order to allow autonomously driving vehicles or inorder to increase the performance of active safety concepts. Thus,various FiP-based sensors may be combined with other FiP-based sensorsand/or conventional sensors, such as in the windows like rear window,side window or front window, on the bumpers or on the lights.

A combination of a FiP-sensor with one or more rain detection sensors isalso possible. This is due to the fact that FiP-devices generally areadvantageous over conventional sensor techniques such as radar,specifically during heavy rain. A combination of at least one FiP-devicewith at least one conventional sensing technique such as radar may allowfor a software to pick the right combination of signals according to theweather conditions.

Further, FiP-devices generally may be used as break assist and/orparking assist and/or for speed measurements. Speed measurements can beintegrated in the vehicle or may be used outside the vehicle, such as inorder to measure the speed of other cars in traffic control. Further,FiP-devices may be used for detecting free parking spaces in parkinglots.

Further, FiP-devices may be used is the fields of medical systems andsports. Thus, in the field of medical technology, surgery robotics, e.g.for use in endoscopes, may be named, since, as outlined above,FiP-devices may require a low volume only and may be integrated intoother devices. Specifically, FiP-devices having one lens, at most, maybe used for capturing 3D information in medical devices such as inendoscopes. Further, FiP-devices may be combined with an appropriatemonitoring software, in order to enable tracking and analysis ofmovements. These applications are specifically valuable e.g. in medicaltreatments and long-distance diagnosis and tele-medicine.

Further, FiP-devices may be applied in the field of sports andexercising, such as for training, remote instructions or competitionpurposes. Specifically, FiP-devices may be applied in the field ofdancing, aerobic, football, soccer, basketball, baseball, cricket,hockey, track and field, swimming, polo, handball, volleyball, rugby,sumo, judo, fencing, boxing etc. FIR-devices can be used to detect theposition of a ball, a bat, a sword, motions, etc., both in sports and ingames, such as to monitor the game, support the referee or for judgment,specifically automatic judgment, of specific situations in sports, suchas for judging whether a point or a goal actually was made.

FiP-devices further may be used in rehabilitation and physiotherapy, inorder to encourage training and/or in order to survey and correctmovements. Therein, the FiP-devices may also be applied for distancediagnostics.

Further, FiP-devices may be applied in the field of machine vision.Thus, one or more FiP-devices may be used e.g. as a passive controllingunit for autonomous driving and or working of robots. In combinationwith moving robots, FiP-devices may allow for autonomous movement and/orautonomous detection of failures in parts. FiP-devices may also be usedfor manufacturing and safety surveillance, such as in order to avoidaccidents including but not limited to collisions between robots,production parts and living beings. Given the passive nature ofFiP-devices, FiP-devices may be advantageous over active devices and/ormay be used complementary to existing solutions like radar, ultrasound,2D cameras, IR detection etc. One particular advantage of FiP-devices isthe low likelihood of signal interference. Therefore multiple sensorscan work at the same time in the same environment, without the risk ofsignal interference. Thus, FP-devices generally may be useful in highlyautomated production environments like e.g. but not limited toautomotive, mining, steel, etc. FiP-devices can also be used for qualitycontrol in production, e.g. in combination with other sensors like 2-Dimaging, radar, ultrasound, IR etc., such as for quality control orother purposes. Further, FiP-devices may be used for assessment ofsurface quality, such as for surveying the surface evenness of a productor the adherence to specified dimensions, from the range of micrometersto the range of meters. Other quality control applications are feasible.

Further, FiP-devices may be used in the polls, airplanes, ships,spacecrafts and other traffic applications. Thus, besides theapplications mentioned above in the context of traffic applications,passive tracking systems for aircrafts, vehicles and the like may benamed. Detection devices based on the FiP-effect for monitoring thespeed and/or the direction of moving objects are feasible. Specifically,the tracking of fast moving objects on land, sea and in the airincluding space may be named. The at least one FiP-detector specificallymay be mounted on a still-standing and/or on a moving device. An outputsignal of the at least one FiP-device can be combined e.g. with aguiding mechanism for autonomous or guided movement of another object.Thus, applications for avoiding collisions or for enabling collisionsbetween the tracked and the steered object are feasible. FiP-devicesgenerally are useful and advantageous due to the low calculation powerrequired, the instant response and due to the passive nature of thedetection system which generally is more difficult to detect and todisturb as compared to active systems, like e.g. radar. FiP-devices areparticularly useful but not limited to e.g. speed control and airtraffic control devices.

FiP-devices generally may be used in passive applications. Passiveapplications include guidance for ships in harbors or in dangerousareas, and for aircrafts at landing or starting. Wherein, fixed, knownactive targets may be used for precise guidance. The same can be usedfor vehicles driving in dangerous but well defined routes, such asmining vehicles.

Further, as outlined above, FiP-devices may be used in the field ofgaming. Thus, FiP-devices can be passive for use with multiple objectsof the same or of different size, color, shape, etc., such as formovement detection in combination with software that incorporates themovement into its content. In particular, applications are feasible inimplementing movements into graphical output. Further, applications ofFiP-devices for giving commands are feasible, such as by using one ormore FiP-devices for gesture or facial recognition. FiP-devices may becombined with an active system in order to work under e.g. low lightconditions or in other situations in which enhancement of thesurrounding conditions is required. Additionally or alternatively, acombination of one or more FiP-devices with one or more IR or VIS lightsources is possible, such as with a detection device based on the HPeffect. A combination of a File-based detector with special devices isalso possible, which can be distinguished easily by the system and itssoftware, e.g. and not limited to, a special color, shape, relativeposition to other devices, speed of movement, light, frequency used tomodulate light sources on the device, surface properties, material used,reflection properties, transparency degree, absorption characteristics,etc. The device can, amongst other possibilities, resemble a stick, aracquet, a club, a gun, a knife, a wheel, a ring, a steering wheel, abottle, a ball, a glass, a vase, a spoon, a fork, a cube, a dice, afigure, a puppet, a teddy, a beaker, a pedal, a switch, a glove,jewelry, a musical instrument or an auxiliary device for playing amusical instrument, such as a plectrum, a drumstick or the like. Otheroptions are feasible.

Further, FiP-devices generally may be used in the field of building,construction and cartography. Thus, generally, FiP-based devices may beused in order to measure and/or monitor environmental areas, e.g.country side or buildings. Therein, one or more FiP-devices may becombined with other methods and devices or can be used solely in orderto monitor progress and accuracy of building projects, changing objects,houses, etc. FiP-devices can be used for generating three-dimensionalmodels of scanned environments, in order to construct maps of rooms,streets, houses, communities or landscapes, both from ground or fromair. Potential fields of application may be construction, cartography,real estate management, land surveying or the like.

FiP-based devices can further be used for scanning of objects, such asin combination with CAD or similar software, such as for additivemanufacturing and/or 3D printing. Therein, use may be made of the highdimensional accuracy of FiP-devices, e.g. in x-, y- or z-direction or inany arbitrary combination of these directions, such as simultaneously.Further, FiP-devices may be used in inspections and maintenance, such aspipeline inspection gauges.

As outlined above, FiP-devices may further be used in manufacturing,quality control or identification applications, such as in productidentification or size identification (such as for finding an optimalplace or package, for reducing waste etc.). Further, FIR-devices may beused in logisitics applications. Thus, FiP-devices may be used foroptimized loading or packing containers or vehicles. Further,FIR-devices may be used for monitoring or controlling of surface damagesin the field of manufacturing, for monitoring or controlling rentalobjects such as rental vehicles, and/or for insurance applications, suchas for assessment of damages. Further, FiP-devices may be used foridentifying a size of material, object or tools, such as for optimalmaterial handling, especially in combination with robots. Further,FiP-devices may be used for process control in production, e.g. forobserving filling level of tanks. Further, FiP-devices may be used formaintenance of production assets like, but not limited to, tanks, pipes,reactors, tools etc. Further, FiP-devices may be used for analyzing3D-quality marks. Further, FiP-devices may be used in manufacturingtailor-made goods such as tooth inlays, dental braces, prosthesis,clothes or the like. FiP-devices may also be combined with one or more3D-printers for rapid prototyping, 3D-copying or the like. Further,FiP-devices may be used for detecting the shape of one or more articles,such as for anti-product piracy and for anti-counterfeiting purposes.

As outlined above, the at least one optical sensor or, in case aplurality of optical sensors is provided, at least one of the opticalsensors may be an organic optical sensor comprising a photosensitivelayer setup having at least two electrodes and at least one photovoltaicmaterial embedded in between these electrodes. In the following,examples of a preferred setup of the photosensitive layer setup will begiven, specifically with regard to materials which may be used withinthis photosensitive layer setup. The photosensitive layer setuppreferably is a photosensitive layer setup of a solar cell, morepreferably an organic solar cell and/or a dye-sensitized solar cell(DSC), more preferably a solid dye-sensitized solar cell (sDSC). Otherembodiments, however, are feasible.

Preferably, the photosensitive layer setup comprises at least onephotovoltaic material, such as at least one photovoltaic layer setupcomprising at least two layers, sandwiched between the first electrodeand the second electrode. Preferably, the photosensitive layer setup andthe photovoltaic material comprise at least one layer of ann-semiconducting metal oxide, at least one dye and at least onep-semiconducting organic material. As an example, the photovoltaicmaterial may comprise a layer setup having at least one dense layer ofan n-semiconducting metal oxide such as titanium dioxide, at least onenano-porous layer of an n-semiconducting metal oxide contacting thedense layer of the n-semiconducting metal oxide, such as at least onenano-porous layer of titanium dioxide, at least one dye sensitizing thenano-porous layer of the n-semiconducting metal oxide, preferably anorganic dye, and at least one layer of at least one p-semiconductingorganic material, contacting the dye and/or the nano-porous layer of then-semiconducting metal oxide.

The dense layer of the n-semiconducting metal oxide, as will beexplained in further detail below, may form at least one barrier layerin between the first electrode and the at least one layer of thenano-porous n-semiconducting metal oxide. It shall be noted, however,that other embodiments are feasible, such as embodiments having othertypes of buffer layers.

The at least two electrodes comprise at least one first electrode and atleast one second electrode. The first electrode may be one of an anodeor a cathode, preferably an anode. The second electrode may be the otherone of an anode or a cathode, preferably a cathode. The first electrodepreferably contacts the at least one layer of the n-semiconducting metaloxide, and the second electrode preferably contacts the at least onelayer of the p-semiconducting organic material. The first electrode maybe a bottom electrode, contacting a substrate, and the second electrodemay be a top electrode facing away from the substrate. Alternatively,the second electrode may be a bottom electrode, contacting thesubstrate, and the first electrode may be the top electrode facing awayfrom the substrate. Preferably, one or both of the first electrode andthe second electrode are transparent.

In the following, some options regarding the first electrode, the secondelectrode and the photovoltaic material, preferably the layer setupcomprising two or more photovoltaic materials, will be disclosed. Itshall be noted, however, that other embodiments are feasible.

a) Substrate, First Electrode and n-Semiconductive Metal Oxide

Generally, for preferred embodiments of the first electrode and then-semiconductive metal oxide, reference may be made to WO 2012/110924A1, U.S. provisional application No. 61/739,173 or U.S. provisionalapplication No. 61/708,058, the full content of all of which is herewithincluded by reference. Other embodiments are feasible.

In the following, it shall be assumed that the first electrode is thebottom electrode directly or indirectly contacting the substrate. Itshall be noted, however, that other setups are feasible, with the firstelectrode being the top electrode.

The n-semiconductive metal oxide which may be used in the photosensitivelayer setup, such as in at least one dense film (also referred to as asolid film) of the n-semiconductive metal oxide and/or in at least onenano-porous film (also referred to as a nano-particulate film) of then-semiconductive metal oxide, may be a single metal oxide or a mixtureof different oxides. It is also possible to use mixed oxides. Then-semiconductive metal oxide may especially be porous and/or be used inthe form of a nanoparticulate oxide, nanoparticles in this context beingunderstood to mean particles which have an average particle size of lessthan 0.1 micrometer. A nanoparticulate oxide is typically applied to aconductive substrate (i.e. a carrier with a conductive layer as thefirst electrode) by a sintering process as a thin porous film with largesurface area.

Preferably, the optical sensor uses at least one transparent substrate.However, setups using one or more intransparent substrates are feasible.

The substrate may be rigid or else flexible. Suitable substrates (alsoreferred to hereinafter as carriers) are, as well as metal foils, inparticular plastic sheets or films and especially glass sheets or glassfilms. Particularly suitable electrode materials, especially for thefirst electrode according to the above-described, preferred structure,are conductive materials, for example transparent conductive oxides(TCOs), for example fluorine- and/or indium-doped tin oxide (FTO or ITO)and/or aluminum-doped zinc oxide (AZO), carbon nanotubes or metal films.Alternatively or additionally, it would, however, also be possible touse thin metal films which still have a sufficient transparency. In casean intransparent first electrode is desired and used, thick metal filmsmay be used.

The substrate can be covered or coated with these conductive materials.Since generally, only a single substrate is required in the structureproposed, the formation of flexible cells is also possible. This enablesa multitude of end uses which would be achievable only with difficulty,if at all, with rigid substrates, for example use in bank cards,garments, etc.

The first electrode, especially the TCO layer, may additionally becovered or coated with a solid or dense metal oxide buffer layer (forexample of thickness 10 to 200 nm), in order to prevent direct contactof the p-type semiconductor with the TCO layer (see Peng et al, Coord.Chem. Rev. 248, 1479 (2004)). The use of solid p-semiconductingelectrolytes, in the case of which contact of the electrolyte with thefirst electrode is greatly reduced compared to liquid or gel-formelectrolytes, however, makes this buffer layer unnecessary in manycases, such that it is possible in many cases to dispense with thislayer, which also has a current-limiting effect and can also worsen thecontact of the n-semiconducting metal oxide with the first electrode.This enhances the efficiency of the components. On the other hand, sucha buffer layer can in turn be utilized in a controlled manner in orderto match the current component of the dye solar cell to the currentcomponent of the organic solar cell. In addition, in the case of cellsin which the buffer layer has been dispensed with, especially in solidcells, problems frequently occur with unwanted recombinations of chargecarriers. In this respect, buffer layers are advantageous in many casesspecifically in solid cells.

As is well known, thin layers or films of metal oxides are generallyinexpensive solid semiconductor materials (n-type semiconductors), butthe absorption thereof, due to large bandgaps, is typically not withinthe visible region of the electromagnetic spectrum, but rather usuallyin the ultraviolet spectral region. For use in solar cells, the metaloxides therefore generally, as is the case in the dye solar cells, haveto be combined with a dye as a photosensitizer, which absorbs in thewavelength range of sunlight, i.e. at 300 to 2000 nm, and, in theelectronically excited state, injects electrons into the conduction bandof the semiconductor. With the aid of a solid p-type semiconductor usedadditionally in the cell as, an electrolyte, which is in turn reduced atthe counter electrode, electrons can be recycled to the sensitizer, suchthat it is regenerated.

Of particular interest for use in organic solar cells are thesemiconductors zinc oxide, tin dioxide, titanium dioxide or mixtures ofthese metal oxides. The metal oxides can be used in the form ofmicrocrystalline or nanocrystalline porous layers. These layers have alarge surface area which is coated with the dye as a sensitizer, suchthat a high absorption of sunlight is achieved. Metal oxide layers whichare structured, for example nanorods, give advantages such as higherelectron mobilities, improved pore filling by the dye, improved surfacesensitization by the dye or increased surface areas.

The metal oxide semiconductors can be used alone or in the form ofmixtures. It is also possible to coat a metal oxide with one or moreother metal oxides. In addition, the metal oxides may also be applied asa coating to another semiconductor, for example GaP, ZnP or ZnS.

Particularly preferred semiconductors are zinc oxide and titaniumdioxide in the anatase polymorph, which is preferably used innanocrystalline form.

In addition, the sensitizers can advantageously be combined with alln-type semiconductors which typically find use in these solar cells.Preferred examples include metal oxides used in ceramics, such astitanium dioxide, zinc oxide, tin(IV) oxide, tungsten(VI) oxide,tantalum(V) oxide, niobium(V) oxide, cesium oxide, strontium titanate,zinc stannate, complex oxides of the perovskite type, for example bariumtitanate, and binary and ternary iron oxides, which may also be presentin nanocrystalline or amorphous form.

Due to the strong absorption that customary organic dyes and ruthenium,phthalocyanines and porphyrins have, even thin layers or films of then-semiconducting metal oxide are sufficient to absorb the requiredamount of dye. Thin metal oxide films in turn have the advantage thatthe probability of unwanted recombination processes falls and that theinternal resistance of the dye subcell is reduced. For then-semiconducting metal oxide, it is possible with preference to uselayer thicknesses of 100 nm up to 20 micrometers, more preferably in therange between 500 nm and approx. 3 micrometers.

b) Dye

In the context of the present invention, as usual in particular forDSCs, the terms “dye”, “sensitizer dye” and “sensitizer” are usedessentially synonymously without any restriction of possibleconfigurations. Numerous dyes which are usable in the context of thepresent invention are known from the prior art, and so, for possiblematerial examples, reference may also be made to the above descriptionof the prior art regarding dye solar cells. As a preferred example, oneor more of the dyes disclosed in WO 2012/110924 A1, U.S. provisionalapplication No. 61/739,173 or U.S. provisional application No.61/708,058 may be used, the full content of all of which is herewithincluded by reference. Additionally or alternatively, one or more of thedyes as disclosed in WO 2007/054470 A1 and/or WO 2013/144177 A1 and/orWO 2012/085803 A1 may be used, the full content of which is included byreference, too.

Dye-sensitized solar cells based on titanium dioxide as a semiconductormaterial are described, for example, in U.S. Pat. No. 4,927,721, Nature353, p. 737-740 (1991) and U.S. Pat. No. 5,350,644, and also Nature 395,p. 583-585 (1998) and EP-A-1 176 646. The dyes described in thesedocuments can in principle also be used advantageously in the context ofthe present invention. These dye solar cells preferably comprisemonomolecular films of transition metal complexes, especially rutheniumcomplexes, which are bonded to the titanium dioxide layer via acidgroups as sensitizers.

Many sensitizers which have been proposed include metal-free organicdyes, which are likewise also usable in the context of the presentinvention. High efficiencies of more than 4%, especially in solid dyesolar cells, can be achieved, for example, with indoline dyes (see, forexample, Schmidt-Mende et al., Adv. Mater. 2005, 17, 813). U.S. Pat. No.6,359,211 describes the use, also implementable in the context of thepresent invention, of cyanine, oxazine, thiazine and acridine dyes whichhave carboxyl groups bonded via an alkylene radical for fixing to thetitanium dioxide semiconductor.

Preferred sensitizer dyes in the dye solar cell proposed are theperylene derivatives, terrylene derivatives and quaterrylene derivativesdescribed in DE 10 2005 053 995 A1 or WO 2007/054470 A1. Further, asoutlined above, one or more of the dyes as disclosed in WO 2012/085803A1 may be used. Additionally or alternatively, one or more of the dyesas disclosed in WO 2013/144177 A1 may be used. The full content of WO2013/144177 A1 and of EP 12162526.3 is herewith included by reference.Specifically, dye D-5 and/or dye R-3 may be used, which is also referredto as ID1338:

Preparation and properties of the Dye D-5 and dye R-3 are disclosed inWO 2013/144177 A1. The use of these dyes, which is also possible in thecontext of the present invention, leads to photovoltaic elements withhigh efficiencies and simultaneously high stabilities.

Further, additionally or alternatively, the following dye may be used,which also is disclosed in WO 2013/144177 A1, which is referred to asID1456:

Further, one or both of the following rylene dyes may be used in thedevices according to the present invention, specifically in the at leastone optical sensor:

These dyes ID1187 and ID1167 fall within the scope of the rylene dyes asdisclosed in WO 2007/054470 A1, and may be synthesized using the generalsynthesis routes as disclosed therein, as the skilled person willrecognize.

The rylenes exhibit strong absorption in the wavelength range ofsunlight and can, depending on the length of the conjugated system,cover a range from about 400 nm (perylene derivatives I from DE 10 2005053 995 A1) up to about 900 nm (quaterrylene derivatives I from DE 102005 053 995 A1). Rylene derivatives I based on terrylene absorb,according to the composition thereof, in the solid state adsorbed ontotitanium dioxide, within a range from about 400 to 800 nm. In order toachieve very substantial utilization of the incident sunlight from thevisible into the near infrared region, it is advantageous to usemixtures of different rylene derivatives I. Occasionally, it may also beadvisable also to use different rylene homologs.

The rylene derivatives I can be fixed easily and in a permanent mannerto the n-semiconducting metal oxide film. The bonding is effected viathe anhydride function (x1) or the carboxyl groups —COOH or —COO— formedin situ, or via the acid groups A present in the imide or condensateradicals ((x2) or (x3)). The rylene derivatives I described in DE 102005 053 995 A1 have good suitability for use in dye-sensitized solarcells in the context of the present invention.

It is particularly preferred when the dyes, at one end of the molecule,have an anchor group which enables the fixing thereof to the n-typesemiconductor film. At the other end of the molecule, the dyespreferably comprise electron donors Y which facilitate the regenerationof the dye after the electron release to the n-type semiconductor, andalso prevent recombination with electrons already released to thesemiconductor.

For further details regarding the possible selection of a suitable dye,it is possible, for example, again to refer to DE 10 2005 053 995 A1 Byway of example, it is possible especially to use ruthenium complexes,porphyrins, other organic sensitizers, and preferably rylenes.

The dyes can be fixed onto or into the n-semiconducting metal oxidefilm, such as the nano-porous n-semiconducting metal oxide layer, in asimple manner. For example, the n-semiconducting metal oxide films canbe contacted in the freshly sintered (still warm) state over asufficient period (for example about 0.5 to 24 h) with a solution orsuspension of the dye in a suitable organic solvent. This can beaccomplished, for example, by immersing the metal oxide-coated substrateinto the solution of the dye.

If combinations of different dyes are to be used, they may, for example,be applied successively from one or more solutions or suspensions whichcomprise one or more of the dyes. It is also possible to use two dyeswhich are separated by a layer of, for example, CuSCN (on this subjectsee, for example, Tennakone, K. J., Phys. Chem. B. 2003, 107, 13758).The most convenient method can be determined comparatively easily in theindividual case.

In the selection of the dye and of the size of the oxide particles ofthe n-semiconducting metal oxide, the organic solar cell should beconfigured such that a maximum amount of light is absorbed. The oxidelayers should be structured such that the solid p-type semiconductor canefficiently fill the pores. For instance, smaller particles have greatersurface areas and are therefore capable of adsorbing a greater amount ofdyes. On the other hand, larger particles generally have larger poreswhich enable better penetration through the p-conductor.

c) p-Semiconducting Organic Material

As described above, the at least one photosensitive layer setup, such asthe photosensitive layer setup of the DSC or sDSC, can comprise inparticular at least one p-semiconducting organic material, preferably atleast one solid p-semiconducting material, which is also designatedhereinafter as p-type semiconductor or p-type conductor. Hereinafter, adescription is given of a series of preferred examples of such organicp-type semiconductors which can be used individually or else in anydesired combination, for example in a combination of a plurality oflayers with a respective p-type semiconductor, and/or in a combinationof a plurality of p-type semiconductors in one layer.

In order to prevent recombination of the electrons in then-semiconducting metal oxide with the solid p-conductor, it is possibleto use, between the n-semiconducting metal oxide and the p-typesemiconductor, at least one passivating layer which has a passivatingmaterial. This layer should be very thin and should as far as possiblecover only the as yet uncovered sites of the n-semiconducting metaloxide. The passivation material may, under some circumstances, also beapplied to the metal oxide before the dye. Preferred passivationmaterials are especially one or more of the following substances: Al₂O₃;silanes, for example CH₃SiCl₃; Al³⁺⁻; 4-tert-butylpyridine (TBP); MgO;GBA (4-guanidinobutyric acid) and similar derivatives; alkyl acids;hexadecylmalonic acid (HDMA).

As described above, preferably one or more solid organic p-typesemiconductors are used—alone or else in combination with one or morefurther p-type semiconductors which are organic or inorganic in nature.In the context of the present invention, a p-type semiconductor isgenerally understood to mean a material, especially an organic material,which is capable of conducting holes, that is to say positive chargecarriers. More particularly, it may be an organic material with anextensive π-electron system which can be oxidized stably at least once,for example to form what is called a free-radical cation. For example,the p-type semiconductor may comprise at least one organic matrixmaterial which has the properties mentioned. Furthermore, the p-typesemiconductor can optionally comprise one or a plurality of dopantswhich intensify the p-semiconducting properties. A significant parameterinfluencing the selection of the p-type semiconductor is the holemobility, since this partly determines the hole diffusion length (cf.Kumara, G., Langmuir, 2002, 18, 10493-10495). A comparison of chargecarrier mobilities in different spiro compounds can be found, forexample, in T. Saragi, Adv. Funct. Mater. 2006, 16, 966-974.

Preferably, in the context of the present invention, organicsemiconductors are used (i.e. one or more of low molecular weight,oligomeric or polymeric semiconductors or mixtures of suchsemiconductors). Particular preference is given to p-type semiconductorswhich can be processed from a liquid phase. Examples here are p-typesemiconductors based on polymers such as polythiophene andpolyarylamines, or on amorphous, reversibly oxidizable, nonpolymericorganic compounds, such as the spirobifluorenes mentioned at the outset(cf., for example, US 2006/0049397 and the spiro compounds disclosedtherein as p-type semiconductors, which are also usable in the contextof the present invention). Preference is also given to using lowmolecular weight organic semiconductors, such as the low molecularweight p-type semiconducting materials as disclosed in WO 2012/110924A1, preferably spiro-MeOTAD, and/or one or more of the p-typesemiconducting materials disclosed in Leijtens et al., ACS Nano, VOL. 6,NO. 2, 1455-1462 (2012). Additionally or alternatively, one or more ofthe p-type semiconducting materials as disclosed in WO 2010/094636 A1may be used, the full content of which is herewith included byreference. In addition, reference may also be made to the remarksregarding the p-semiconducting materials and dopants from the abovedescription of the prior art.

The p-type semiconductor is preferably producible or produced byapplying at least one p-conducting organic material to at least onecarrier element, wherein the application is effected for example bydeposition from a liquid phase comprising the at least one p-conductingorganic material. The deposition can in this case once again beeffected, in principle, by any desired deposition process, for exampleby spin-coating, doctor blading, knife-coating, printing or combinationsof the stated and/or other deposition methods.

The organic p-type semiconductor may especially comprise at least onespiro compound such as spiro-MeOTAD and/or at least one compound withthe structural formula:

in whichA¹, A², A³ are each independently optionally substituted aryl groups orheteroaryl groups,R², R³ are each independently selected from the group consisting of thesubstituents —R, —OR, —NR₂, -A⁴-OR and -A⁴-NR₂,where R is selected from the group consisting of alkyl, aryl andheteroaryl,andwhere A⁴ is an aryl group or heteroaryl group, andwhere n at each instance in formula I is independently a value of 0, 1,2 or 3,with the proviso that the sum of the individual n values is at least 2and at least two of the R¹, R² and R³ radicals are —OR and/or —NR₂.

Preferably, A² and A³ are the same; accordingly, the compound of theformula (I) preferably has the following structure (Ia)

More particularly, as explained above, the p-type semiconductor may thushave at least one low molecular weight organic p-type semiconductor. Alow molecular weight material is generally understood to mean a materialwhich is present in monomeric, nonpolymerized or nonoligomerized form.The term “low molecular weight” as used in the present contextpreferably means that the p-type semiconductor has molecular weights inthe range from 100 to 25 000 g/mol. Preferably, the low molecular weightsubstances have molecular weights of 500 to 2000 g/mol.

In general, in the context of the present invention, p-semiconductingproperties are understood to mean the property of materials, especiallyof organic molecules, to form holes and to transport these holes and/orto pass them on to adjacent molecules. More particularly, stableoxidation of these molecules should be possible. In addition, the lowmolecular weight organic p-type semiconductors mentioned may especiallyhave an extensive π-electron system. More particularly, the at least onelow molecular weight p-type semiconductor may be processable from asolution. The low molecular weight p-type semiconductor may especiallycomprise at least one triphenylamine. It is particularly preferred whenthe low molecular weight organic p-type semiconductor comprises at leastone spiro compound. A Spiro compound is understood to mean polycyclicorganic compounds whose rings are joined only at one atom, which is alsoreferred to as the Spiro atom. More particularly, the spiro atom may bespa-hybridized, such that the constituents of the spiro compoundconnected to one another via the spiro atom are, for example, arrangedin different planes with respect to one another.

More preferably, the spiro compound has a structure of the followingformula:

where the aryl¹, aryl², aryl³, aryl⁴, aryl⁵, aryl⁶, aryl⁷, and aryl⁸radicals are each independently selected from substituted aryl radicalsand heteroaryl radicals, especially from substituted phenyl radicals,where the aryl radicals and heteroaryl radicals, preferably the phenylradicals, are each independently substituted, preferably in each case byone or more substituents selected from the group consisting of —O-alkyl,—OH, —F, —Cl, —Br and —I, where alkyl is preferably methyl, ethyl,propyl or isopropyl. More preferably, the phenyl radicals are eachindependently substituted, in each case by one or more substituentsselected from the group consisting of —O-Me, —OH, —F, —Cl, —Br and —I.

Further preferably, the Spiro compound is a compound of the followingformula:

where R^(r), R^(s), R^(l), R^(u), R^(v), R^(w), R^(x) and R^(y) are eachindependently selected from the group consisting of —O-alkyl, —OH, —F,—Cl, —Br and —I, where alkyl is preferably methyl, ethyl, propyl orisopropyl. More preferably, R^(r), R^(s), R^(t), R^(u), R^(v), R^(w),R^(x) and R^(y) are each independently selected from the groupconsisting of —O-Me, —OH, —F, —Cl, —Br and —I.

More particularly, the p-type semiconductor may comprise spiro-MeOTAD orconsist of spiro-MeOTAD, i.e. a compound of the formula below,commercially available from Merck KGaA, Darmstadt, Germany:

Alternatively or additionally, it is also possible to use otherp-semiconducting compounds, especially low molecular weight and/oroligomeric and/or polymeric p-semiconducting compounds.

In an alternative embodiment, the low molecular weight organic p-typesemiconductor comprises one or more compounds of the above-mentionedgeneral formula I, for which reference may be made, for example, to PCTapplication number PCT/EP2010/051826. The p-type semiconductor maycomprise the at least one compound of the above-mentioned generalformula I additionally or alternatively to the Spiro compound describedabove.

The term “alkyl” or “alkyl group” or “alkyl radical” as used in thecontext of the present invention is understood to mean substituted orunsubstituted C₁-C₂₀-alkyl radicals in general. Preference is given toC₁- to C₁₀-alkyl radicals, particular preference to C₁- to C₈-alkylradicals. The alkyl radicals may be either straight-chain or branched.In addition, the alkyl radicals may be substituted by one or moresubstituents selected from the group consisting of C₁-C₂₀-alkoxy,halogen, preferably F, and C₆-C₃₀-aryl which may in turn be substitutedor unsubstituted. Examples of suitable alkyl groups are methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl and octyl, and also isopropyl,isobutyl, isopentyl, sec-butyl, tert-butyl, neopentyl,3,3-dimethylbutyl, 2-ethylhexyl, and also derivatives of the alkylgroups mentioned substituted by C₆-C₃₀-aryl, C₁-C₂₀-alkoxy and/orhalogen, especially F, for example CF₃.

The term “aryl” or “aryl group” or “aryl radical” as used in the contextof the present invention is understood to mean optionally substitutedC₆-C₃₀-aryl radicals which are derived from monocyclic, bicyclic,tricyclic or else multicyclic aromatic rings, where the aromatic ringsdo not comprise any ring heteroatoms. The aryl radical preferablycomprises 5- and/or 6-membered aromatic rings. When the aryls are notmonocyclic systems, in the case of the term “aryl” for the second ring,the saturated form (perhydro form) or the partly unsaturated form (forexample the dihydro form or tetrahydro form), provided the particularforms are known and stable, is also possible. The term “aryl” in thecontext of the present invention thus comprises, for example, alsobicyclic or tricyclic radicals in which either both or all threeradicals are aromatic, and also bicyclic or tricyclic radicals in whichonly one ring is aromatic, and also tricyclic radicals in which tworings are aromatic. Examples of aryl are: phenyl, naphthyl, indanyl,1,2-dihydronaphthenyl, 1,4-dihydronaphthenyl, fluorenyl, indenyl,anthracenyl, phenanthrenyl or 1,2,3,4-tetrahydronaphthyl. Particularpreference is given to C₆-C₁₀-aryl radicals, for example phenyl ornaphthyl, very particular preference to C₆-aryl radicals, for examplephenyl. In addition, the term “aryl” also comprises ring systemscomprising at least two monocyclic, bicyclic or multicyclic aromaticrings joined to one another via single or double bonds. One example isthat of biphenyl groups.

The term “heteroaryl” or “heteroaryl group” or “heteroaryl radical” asused in the context of the present invention is understood to meanoptionally substituted 5- or 6-membered aromatic rings and multicyclicrings, for example bicyclic and tricyclic compounds having at least oneheteroatom in at least one ring. The heteroaryls in the context of theinvention preferably comprise 5 to 30 ring atoms. They may bemonocyclic, bicyclic or tricyclic, and some can be derived from theaforementioned aryl by replacing at least one carbon atom in the arylbase skeleton with a heteroatom. Preferred heteroatoms are N, O and S.The hetaryl radicals more preferably have 5 to 13 ring atoms. The baseskeleton of the heteroaryl radicals is especially preferably selectedfrom systems such as pyridine and five-membered heteroaromatics such asthiophene, pyrrole, imidazole or furan. These base skeletons mayoptionally be fused to one or two six-membered aromatic radicals. Inaddition, the term “heteroaryl” also comprises ring systems comprisingat least two monocyclic, bicyclic or multicyclic aromatic rings joinedto one another via single or double bonds, where at least one ringcomprises a heteroatom. When the heteroaryls are not monocyclic systems,in the case of the term “heteroaryl” for at least one ring, thesaturated form (perhydro form) or the partly unsaturated form (forexample the dihydro form or tetrahydro form), provided the particularforms are known and stable, is also possible. The term “heteroaryl” inthe context of the present invention thus comprises, for example, alsobicyclic or tricyclic radicals in which either both or all threeradicals are aromatic, and also bicyclic or tricyclic radicals in whichonly one ring is aromatic, and also tricyclic radicals in which tworings are aromatic, where at least one of the rings, i.e. at least onearomatic or one nonaromatic ring, has a heteroatom. Suitable fusedheteroaromatics are, for example, carbazolyl, benzimidazolyl,benzofuryl, dibenzofuryl or dibenzothiophenyl. The base skeleton may besubstituted at one, more than one or all substitutable positions,suitable substituents being the same as have already been specifiedunder the definition of C₆-C₃₀-aryl. However, the hetaryl radicals arepreferably unsubstituted. Suitable hetaryl radicals are, for example,pyridin-2-yl, pyridin-3-yl, pyridin-4-yl, thiophen-2-yl, thiophen-3-yl,pyrrol-2-yl, pyrrol-3-yl, furan-2-yl, furan-3-yl and imidazol-2-yl andthe corresponding benzofused radicals, especially carbazolyl,benzimidazolyl, benzofuryl, dibenzofuryl or dibenzothiophenyl.

In the context of the invention, the term “optionally substituted”refers to radicals in which at least one hydrogen radical of an alkylgroup, aryl group or heteroaryl group has been replaced by asubstituent. With regard to the type of this substituent, preference isgiven to alkyl radicals, for example methyl, ethyl, propyl, butyl,pentyl, hexyl, heptyl and octyl, and also isopropyl, isobutyl,isopentyl, sec-butyl, tert-butyl, neopentyl, 3,3-dimethylbutyl and2-ethylhexyl, aryl radicals, for example C₆-C₁₀-aryl radicals,especially phenyl or naphthyl, most preferably C₆-aryl radicals, forexample phenyl, and hetaryl radicals, for example pyridin-2-yl,pyridin-3-yl, pyridin-4-yl, thiophen-2-yl, thiophen-3-yl, pyrrol-2-yl,pyrrol-3-yl, furan-2-yl, furan-3-yl and imidazol-2-yl, and also thecorresponding benzofused radicals, especially carbazolyl,benzimidazolyl, benzofuryl, dibenzofuryl or dibenzothiophenyl. Furtherexamples include the following substituents: alkenyl, alkynyl, halogen,hydroxyl.

The degree of substitution here may vary from monosubstitution up to themaximum number of possible substituents.

Preferred compounds of the formula I for use in accordance with theinvention are notable in that at least two of the R¹, R² and R³ radicalsare para-OR and/or —NR₂ substituents. The at least two radicals here maybe only —OR radicals, only —NR₂ radicals, or at least one —OR and atleast one —NR₂ radical.

Particularly preferred compounds of the formula I for use in accordancewith the invention are notable in that at least four of the R¹, R² andR³ radicals are para-OR and/or —NR₂ substituents. The at least fourradicals here may be only —OR radicals, only —NR₂ radicals or a mixtureof —OR and —NR₂ radicals.

Very particularly preferred compounds of the formula I for use inaccordance with the invention are notable in that all of the R¹, R² andR³ radicals are para-OR and/or —NR₂ substituents. They may be only —ORradicals, only —NR₂ radicals or a mixture of —OR and —NR₂ radicals.

In all cases, the two R in the —NR₂ radicals may be different from oneanother, but they are preferably the same.

Preferably, A¹, A² and A³ are each independently selected from the groupconsisting of

in which

-   m is an integer from 1 to 18,-   R⁴ is alkyl, aryl or heteroaryl, where R⁴ is preferably an aryl    radical, more preferably a phenyl radical,-   R⁵, R⁶ are each independently H, alkyl, aryl or heteroaryl,    where the aromatic and heteroaromatic rings of the structures shown    may optionally have further substitution. The degree of substitution    of the aromatic and heteroaromatic rings here may vary from    monosubstitution up to the maximum number of possible substituents.

Preferred substituents in the case of further substitution of thearomatic and heteroaromatic rings include the substituents alreadymentioned above for the one, two or three optionally substitutedaromatic or heteroaromatic groups.

Preferably, the aromatic and heteroaromatic rings of the structuresshown do not have further substitution.

More preferably, A¹, A² and A³ are each independently

more preferably

More preferably, the at least one compound of the formula (I) has one ofthe following structures

In an alternative embodiment, the organic p-type semiconductor comprisesa compound of the type ID322 having the following structure:

The compounds for use in accordance with the invention can be preparedby customary methods of organic synthesis known to those skilled in theart. References to relevant (patent) literature can additionally befound in the synthesis examples adduced below.

d) Second Electrode

The second electrode may be a bottom electrode facing the substrate orelse a top electrode facing away from the substrate. As outlined above,the second electrode may be fully or partially transparent or, else, maybe intransparent. As used herein, the term partially transparent refersto the fact that the second electrode may comprise transparent regionsand intransparent regions.

One or more materials of the following group of materials may be used:at least one metallic material, preferably a metallic material selectedfrom the group consisting of aluminum, silver, platinum, gold; at leastone nonmetallic inorganic material, preferably LiF; at least one organicconductive material, preferably at least one electrically conductivepolymer and, more preferably, at least one transparent electricallyconductive polymer.

The second electrode may comprise at least one metal electrode, whereinone or more metals in pure form or as a mixture/alloy, such asespecially aluminum or silver may be used.

Additionally or alternatively, nonmetallic materials may be used, suchas inorganic materials and/or organic materials, both alone and incombination with metal electrodes. As an example, the use ofinorganic/organic mixed electrodes or multilayer electrodes is possible,for example the use of LiF/Al electrodes. Additionally or alternatively,conductive polymers may be used. Thus, the second electrode of theoptical sensor preferably may comprise one or more conductive polymers.

Thus, as an example, the second electrode may comprise one or moreelectrically conductive polymers, in combination with one or more layersof a metal. Preferably, the at least one electrically conductive polymeris a transparent electrically conductive polymer. This combinationallows for providing very thin and, thus, transparent metal layers, bystill providing sufficient electrical conductivity in order to renderthe second electrode both transparent and highly electricallyconductive. Thus, as an example, the one or more metal layers, each orin combination, may have a thickness of less than 50 nm, preferably lessthan 40 nm or even less than 30 nm.

As an example, one or more electrically conductive polymers may be used,selected from the group consisting of: polyanaline (PANI) and/or itschemical relatives; a polythiophene and/or its chemical relatives, suchas poly(3-hexylthiophene) (P3HT) and/or PEDOT:PSS(poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)). Additionallyor alternatively, one or more of the conductive polymers as disclosed inEP2507286 A2, EP2205657 A1 or EP2220141 A1. For further exemplaryembodiments, reference may be made to U.S. provisional application No.61/739,173 or U.S. provisional application No. 61/708,058, the fullcontent of all of which is herewith included by reference.

In addition or alternatively, inorganic conductive materials may beused, such as inorganic conductive carbon materials, such as carbonmaterials selected from the group consisting of: graphite, graphene,carbon nano-tubes, carbon nano-wires.

In addition, it is also possible to use electrode designs in which thequantum efficiency of the components is increased by virtue of thephotons being forced, by means of appropriate reflections, to passthrough the absorbing layers at least twice. Such layer structures arealso referred to as “concentrators” and are likewise described, forexample, in WO 02/101838 (especially pages 23-24).

The at least one second electrode of the optical sensor may be a singleelectrode or may comprise a plurality of partial electrodes. Thus, asingle second electrode may be used, or more complex setups, such assplit electrodes.

Further, the at least one second electrode of the at least one opticalsensor, which specifically may be or may comprise at least onelongitudinal optical sensor and/or at least one transversal opticalsensor, preferably may fully or partially be transparent. Thus,specifically, the at least one second electrode may comprise one, two ormore electrodes, such as one electrode or two or more partialelectrodes, and optionally at least one additional electrode materialcontacting the electrode or the two or more partial electrodes.

Further, the second electrode may fully or partially be intransparent.Specifically, the two or more partial electrodes may be intransparent.It may be especially preferable to make the final electrodeintransparent, such as the electrode facing away from the object and/orthe last electrode of a stack of optical sensors. Consequently, thislast electrode can then be optimized to convert all remaining light intoa sensor signal. Herein, the “final” electrode may be the electrode ofthe at least one optical sensor facing away from the object. Generally,intransparent electrodes are more efficient than transparent electrodes.

Thus, it is generally beneficial to reduce the number of transparentsensors and/or the number of transparent electrodes to a minimum. Inthis context, as an example, reference may be made to the potentialsetups of the at least one longitudinal optical sensor and/or to the atleast one transversal optical sensor as shown in WO2014/097181 A1. Othersetups, however, are feasible.

The optical detector, the detector system, the method, the human-machineinterface, the entertainment device, the tracking system, the camera andthe uses of the optical detector provide a large number of advantagesover known devices, methods and uses of this type.

Thus, generally, by combining one or more spatial light modulators withone or more optical sensors, in conjunction with the general idea ofusing modulation frequencies for separating signal components byfrequency analysis, an optical detector may be provided which, in atechnically simple fashion and without the necessity of using pixelatedoptical sensors, may provide the possibility of high-resolution imaging,preferably high-resolution 3D imaging, the possibility of determiningtransversal and/or longitudinal coordinates of en object, thepossibility of separating colors in a simplified fashion and many otherpossibilities.

Thus, current setups of cameras, specifically 3D-cameras, typicallyrequire complex measurement setups and complex measurement algorithms.Within the present invention, large-area optical sensors may be used asa whole, such as solar cells and more preferably DSCs or sDSCs, withoutthe necessity of subdividing these optical sensors into pixels. For thespatial light modulator, as an example, a liquid crystal screen ascommonly used in displays and/or projection devices may be placed aboveone or more solar cells, such as a stack of solar cells, more preferablya stack of DSCs. The DSCs may have the same optical properties and/ordiffering optical properties. Thus, at least two DSCs having differingabsorption properties may be used, such as at least one DSC having anabsorption in the red spectral region, one DSC having an absorption inthe green spectral region, and one DSC having an absorption in the bluespectral region. Other setups are feasible. The DSCs may be combinedwith one or more inorganic sensors, such as one or more CCD chips,specifically one or more intransparent CCD chips having a highresolution, such as used in standard digital cameras. Thus, a stacksetup may be used, having a CCD chip at a position furthest away fromthe spatial light modulator, a stack of one, two or more at leastpartially transparent DSCs or sDSCs, preferably without pixels,specifically for the purpose of determining a longitudinal coordinate ofthe object by using the FiP-effect. This stack may be followed by one ormore spatial light modulators, such as one or more transparent orsemitransparent LCDs and/or one or more devices using the so-called DLPtechnology, as e.g. disclosed inwww.dlp.com/de/technology/how-dlp-works. This stack may be combined withone or more transfer devices, such as one or more camera lens systems.

The frequency analysis may be performed by using standard Fouriertransformation algorithms.

The optional intransparent CCD chip may be used at a high resolution, inorder to obtain x-, y- and color information, as in regular camerasystems. The combination of the SLM and the one or more large-areaoptical sensors may be used for obtaining longitudinal information(z-information). Each of the pixels of the SLM may oscillate, such as byopening and closing at a high frequency, and each of the pixels mayoscillate a well-defined, unique frequency.

The photon-density-dependent transparent DSCs may be used to determinedepth information, which is known as the above-mentioned FiP-effect.Thus, a light beam passing a concentrating lens and two transparent DSCswill cover different surface areas of the sensitive regions of the DSCs.This may cause different photocurrents, from which depth information maybe deduced. The beams passing the solar cells may be pulsed by theoscillating pixels of the SLM, such as the LCD and/or the micro-mirrordevice. Current-voltage information obtained from the DSCs may beprocessed by frequency analysis, such as by Fourier transformation, inorder to obtain the current-voltage information behind each pixel. Thefrequency uniquely may identify each pixel and, thus, its transversalposition (x-y-position). The photocurrent of each pixel may be used inorder to obtain the corresponding depth information, as discussed above.

Further, as discussed above, the optical detector may be realized as amulti-color or full-color detector, adapted for recognizing and/ordetermining colors of the at least one light beam. Thus, generally, theoptical detector may be a multi-color and/or full-color opticaldetector, which may be used in cameras, Thereby, a simple setup may berealized, and a multi-color detector for imaging and/or determining atransversal and/or longitudinal position of at least one object may berealized, in a technically simple fashion. Thus, a spatial lightmodulator having at least two, preferably at least three different typesof pixels of different color may be used.

As an example, a liquid crystal spatial light modulator, such as athin-film transistor spectral light modulator, may be used, preferablyhaving pixels of at least two, preferably at least three differentcolors. These types of spatial light modulators are commerciallyavailable with red, green and blue channels, each of which may be opened(transparent) and closed (black), preferably pixel by pixel.Additionally or alternatively, reflective SLMs may be used, such as byusing the above-mentioned DLP® technology, available by TexasInstruments, having single-color or multi- or even full-colormicro-mirrors. Again, additionally or alternatively, SLMs based on anacousto-optical effect and/or based on an electro-optical effect may beused, such as described in e.g.http://www.leysop.com/integrated_pockels_cell.htm. Thus, as an example,in liquid crystal technology or micro-mirrors, color filters may beused, such as color filters directly on top of the pixels. Thus, eachpixel can open or close a channel wherein light can pass the SLM andproceed towards the at least one optical sensor. The at least oneoptical sensor, such as the at least one DSC or sDSC, may absorb fullyor partially the light-beam passing the SLM. As an example, in case onlythe blue channel is open, only blue light may be absorbed by the opticalsensor. When red, green and blue light are pulsed out of phase and/or ata differing frequency, the frequency analysis may allow for a detectionof the three colors simultaneously. Thus, generally, the at least oneoptical sensor may be a broad-band optical sensor adapted to absorb inthe spectral regions of the multi-color or full-color SLM. Thus, abroad-band optical sensor may be used which absorbs in the red, thegreen and the blue spectral region. Additionally or alternatively,different optical sensors may be used for different spectral regions.Generally, the above-mentioned frequency analysis may be adapted toidentify signal components according to their frequency and/or phase ofmodulation. Thus, by identifying the frequency and/or the phase of thesignal components, the signal components may be assigned to a specificcolor component of the light beam. Thus, the evaluation device may beadapted to separate the light beam into differing colors.

When two or more channels are pulsed at different modulationfrequencies, i.e. at different frequencies and/or different phases,there may be times at which each channel may be individually open, allchannels open and two different channels open simultaneously. Thisallows to detect a larger number of different colors simultaneously,with little additional post-processing. For detecting multiple channelsignals, accuracy or color selectivity may be increased, whenone-channel and multi-channel signals may be compared in thepost-processing.

As outlined above, the spatial light modulator may be embodied invarious ways. Thus, as an example, the spatial light modulator may useliquid crystal technology, preferably in conjunction with thin-filmtransistor (TFT) technology. Additionally or alternatively,micromechanical devices may be used, such as reflective micromechanicaldevices, such as micro-mirror devices according to the DLP® technologyavailable by Texas Instruments. Additionally or alternatively,electrochromic and/or dichroitic filters may be used as spatial lightmodulators. Additionally or alternatively, one or more of electrochromicspatial light modulators, acousto-optical spatial light modulators orelectro-optical spatial light modulators may be used. Generally, thespatial light modulator may be adapted to modulate the at least oneoptical property of the light beam in various ways, such as by switchingthe pixels between a transparent state and an intransparent state, atransparent state and a more transparent state, or a transparent stateand a color state.

Further embodiments relate to a beam path of the light beam or a partthereof within the optical detector. As used herein and as used in thefollowing, a “beam path” generally is a path along which a light beam ora part thereof may propagate. Thus, generally, the light beam within theoptical detector may travel along a single beam path. The single beampath may be a straight single beam path or may be a beam path having oneor more deflections, such as a folded beam path, a branched beam path, arectangular beam path or a Z-shaped beam path. Alternatively, two ormore beam paths may be present within the optical detector. Thus, thelight beam entering the optical detector may be split into two or morepartial light beams, each of the partial light beams following one ormore partial beam paths. Each of the partial beam paths, independently,may be a straight partial beam path or, as outlined above, a partialbeam path having one or more deflections, such as a folded partial beampath, a rectangular partial beam path or a Z-shaped partial beam path.Generally, any type of combination of various types of beam paths isfeasible, as the skilled person will recognize. Thus, at least twopartial beam paths may be present, forming, in total, a W-shaped setup.

By splitting the beam path into two or more partial beam paths, theelements of the optical detector may be distributed over the two or morepartial beam paths. Thus, at least one optical sensor, such as at leastone large-area optical sensor and/or at least one stack of large-areaoptical sensors, such as one or more optical sensors having theabove-mentioned FiP-effect, may be located in a first partial beam path.At least one additional optical sensor, such as an intransparent opticalsensor, e.g. an image sensor such as a CCD sensor and/or a CMOS sensormay be located in a second partial beam path. Further, the at least onespatial light modulator may be located in one or more of the partialbeam paths and/or may be located in a common beam path before splittingthe common beam path into two or more partial beam paths. Various setupsare feasible. Further, the light beam and/or the partial light beam maytravel along the beam path or the partial beam path in a unidirectionalfashion, such as only once or in a single travel fashion. Alternatively,the light beam or the partial light beam may travel along the beam pathor the partial beam path repeatedly, such as in ring-shaped setups,and/or in a bidirectional fashion, such as in a setup in which the lightbeam or the partial light beam is reflected by one or more reflectiveelements, in order to travel back along the same beam path or partialbeam path. The at least one reflector element may be or may comprise thespatial light modulator itself. Similarly, for splitting the beam pathinto two or more partial beam paths, the spatial light modulator itselfmay be used. Additionally or alternatively, other types of reflectiveelements may be used.

By using two or more partial beam paths within the optical detectorand/or by having the light beam or the partial light beam travellingalong the beam path or the partial beam path repeatedly or in abidirectional fashion, various setups of the optical detector arefeasible, which allow for a high flexibility of the setup of the opticaldetector. Thus, the functionalities of the optical detector may be splitand/or distributed over different partial beam paths. Thus, a firstpartial beam path may be dedicated to a z-detection of an object, suchas by using one or more optical sensors having the above-mentionedFiP-effect, and a second beam path may be used for imaging, such as byproviding one or more image sensors such as one or more CCD chips orCMOS chips for imaging. Thus, within one, more than one or all of thepartial beam paths, independent or dependent coordinate systems may bedefined, wherein one or more coordinates of the object may be determinedwithin these coordinate systems. Since the general setup of the opticaldetector is known, the coordinate systems may be correlated, and asimple coordinate transformation may be used for combining thecoordinates in a common coordinate system of the optical detector.

The above-mentioned possibilities may be embodied in various ways. Thus,generally, the spatial light modulator, as outlined above, may be areflective spatial light modulator. Thus, as discussed above, thereflective spatial light modulator may be or may comprise a micro-mirrorsystem, such as by using the above-mentioned DLP® technology. Thus, thespatial light modulator may be used for deflecting or for reflecting thelight beam and/or a part thereof, such as for reflecting the light beaminto its direction of origin. Thus, the at least one optical sensor ofthe optical detector may comprise one transparent optical sensor. Theoptical detector may be setup such that the light beam passes throughthe transparent optical sensor before reaching the spatial lightmodulator. The spatial light modulator may be adapted to at leastpartially reflect the light beam back towards the optical sensor. Inthis embodiment, the light beam may pass the transparent optical sensortwice. Thus, firstly, the light beam may pass through the transparentoptical sensor for the first time in an unmodulated fashion, reachingthe spatial light modulator. The spatial light modulator, as discussedabove, may be adapted to modulate the light beam and, simultaneously,reflect the light beam back towards the transparent optical sensor suchthat the light beam passes the transparent optical sensor for the secondtime, this time in a modulated fashion, in order to be detected by theoptical sensor.

As outlined above, additionally or alternatively, the optical detectormay contain at least one beam-splitting element adapted for dividing thebeam path of the light beam into at least two partial beam paths. Thebeam-splitting element may be embodied in various ways and/or by usingcombinations of beam-splitting elements. Thus, as an example, thebeam-splitting element may comprise at least one element selected fromthe group consisting of: the spatial light modulator, a beam-splittingprism, a grating, a semitransparent mirror, a dichroitic mirror.Combinations of the named elements and/or other elements are feasible.Thus, generally, the at least one beam splitting element may comprisethe at least one spatial light modulator. In this embodiment,specifically, the spatial light modulator may be a reflective spatiallight modulator, such as by using the above-mentioned micro-mirrortechnology, specifically the above-mentioned DLP® technology. Asoutlined above, the elements of the optical detector may be distributedover the beam paths, before and/or after splitting the beam path. Thus,as an example, at least one optical sensor may be located in each of thepartial beam paths. Thus, e.g., at least one stack of optical sensors,such as at least one stack of large-area optical sensors and, morepreferably, at least one stack of optical sensors having theabove-mentioned FiP-effect, may be located in at least one of thepartial beam paths, such as in a first one of the partial beam paths.Additionally or alternatively, at least one intransparent optical sensormay be located in at least one of the partial beam paths, such as in atleast a second one of the partial beam paths. Thus, as an example, atleast one inorganic optical sensor may be located in a second partialbeam path, such as an inorganic semiconductor optical sensor, such as animaging sensor and/or a camera chip, more preferably a CCD chip and/or aCMOS chip, wherein both monochrome chips and/or multi-chrome orfull-color chips may be used. Thus, as outlined above, the first partialbeam path, by using the stack of optical sensors, may be used fordetecting the z-coordinate of the object, and the second partial beampath may be used for imaging, such as by using the imaging sensor,specifically the camera chip.

As outlined above, the spatial light modulator may be part of thebeam-splitting element. Additionally or alternatively, the at least onespatial light modulator and/or at least one of a plurality of spatiallight modulators may, itself, be located in one or more of the partialbeam paths. Thus, as an example, the spatial light modulator may belocated in the first one of the partial beam paths, i.e. in the partialbeam path having the stack of optical sensors, such as the stack ofoptical sensors having the above-mentioned FiP-effect. Thus, the stackof optical sensors may comprise at least one large-area optical sensor,such as at least one large-area optical sensor having the FiP-effect.

In case one or more intransparent optical sensors are used, such as inone or more of the partial beam paths, such as in the second partialbeam path, the intransparent optical sensor preferably may be or maycomprise a pixelated optical sensor, preferably an inorganic pixelatedoptical sensor and more preferably a camera chip, and most preferably atleast one of a CCD chip and CMOS chip. However, other embodiments arefeasible, and combinations of pixelated and non-pixelated intransparentoptical sensors in one or more of the partial optical beam paths arefeasible.

By using the above-mentioned possibilities of more complex setups of theoptical sensor and/or the optical detector, specifically, use may bemade of the high flexibility of spatial light modulators, with regard totheir transparency, reflective properties or other properties. Thus, asoutlined above, the spatial light modulator itself may be used forreflecting or deflecting the light beam or a partial light beam.Therein, linear or non-linear setups of the optical detector may befeasible. Thus, as outlined above, W-shaped setups, Z-shaped setups orother setups are feasible. In case a reflective spatial light modulatoris used, use may be made of the fact that, specifically in micro-mirrorsystems the spatial light modulator is generally adapted to reflect ordeflect the light beam into more than one direction. Thus, a firstpartial beam path may be setup in a first direction of deflection orreflection of the spatial light modulator, and at least one secondpartial beam path may be setup in at least one second direction ofdeflection or reflection of the spatial light modulator. Thus, thespatial light modulator may form a beam-splitting element adapted forsplitting an incident light beam into at least one first direction andat least one second direction. Thus, as an example, the micro-mirrors ofthe spatial light modulator may either be positioned to reflect ordeflect the light beam and/or parts thereof towards at least one firstpartial beam path, such as towards a first partial beam path having astack of optical sensors such as a stack of FiP-sensors, or towards atleast one second partial beam path, such as towards at least one secondpartial beam path having the intransparent optical sensor, such as theimaging sensor, specifically the at least one CCD chip and/or the atleast one CMOS chip. Thereby, the general amount of light illuminatingthe elements in the various beam paths may be increased. Furthermore,this construction may allow obtaining identical pictures, such aspictures having an identical focus, in the two or more partial beampaths, such as on the stack of optical sensors and the imaging sensor,such as the full-color CCD or CMOS sensor.

As opposed to a linear setup, a non-linear setup such as a setup havingtwo or more partial beam paths, such as a branched setup and/or aW-setup, may allow for individually optimizing the setups of the partialbeam paths. Thus, in case the imaging function by the at least oneimaging sensor and the function of the z-detection are separated inseparate partial beam paths, an independent optimization of thesepartial beam paths and the elements disposed therein is feasible. Thus,as an example, different types of optical sensors such as transparentsolar cells may be used in the partial beam path adapted forz-detection, since transparency is less important as in the case inwhich the same light beam has to be used for imaging by the imagingdetector. Thus, combinations with various types of cameras are feasible.As an example, thicker stacks of optical detectors may be used, allowingfor a more accurate z-information. Consequently, even in case the stackof optical sensors should be out of focus, a detection of the z-positionof the object is feasible.

Further, one or more additional elements may be located in one or moreof the partial beam paths. As an example, one or more optical shuttersmay be disposed within one or more of the partial beam paths. Thus, oneor more shutters may be located between the reflective spatial lightmodulator and the stack of optical sensors and/or the intransparentoptical sensor such as the imaging sensor. The shutters of the partialbeam paths may be used and/or actuated independently. Thus, as anexample, one or more imaging sensors, specifically one or more imagingchips such as CCD chips and/or CMOS chips, and the large-area opticalsensor and/or the stack of large area optical sensors generally mayexhibit different types of optimum light responses. In a lineararrangement, only one additional shutter may be possible, such asbetween the large-area optical sensor or stack of large-area opticalsensors and the imaging sensor. In a split setup having two or morepartial beam paths, such as in the above-mentioned W-setup, one or moreshutters may be placed in front of the stack of optical sensors and/orin front of the imaging sensor. Thereby, optimum light intensities forboth types of sensors may be feasible.

Additionally or alternatively, one or more lenses may be disposed withinone or more of the partial beam paths. Thus, one or more lenses may belocated between spatial light modulator, specifically the reflectivespatial light modulator, and the stack of optical sensors and/or betweenthe spatial light modulator and the intransparent optical sensor such asthe imaging sensor. Thus, as an example, by using the one or more lensesin one or more or all of the partial beam paths, a beam shaping may takeplace for the respective partial beams path or partial beam pathscomprising the at least one lens. Thus, the imaging sensor, specificallythe CCD or CMOS sensor, may be adapted to take a 2D picture, whereas theat least one optical sensor such as the optical sensor stack may beadapted to measure a z-coordinate or depth of the object. The focus orthe beam shaping in these partial beam paths, which generally may bedetermined by the respective lenses of these partial beam paths, notnecessarily has to be identical. Thus, the beam properties of thepartial light beams propagating along the partial beam paths may beoptimized individually, such as for imaging, xy-detection orz-detection.

Further embodiments generally refer to the at least one optical sensor.Generally, for potential embodiments of the at least one optical sensor,as outlined above, reference may be made to one or more of the prior artdocuments listed above, such as to WO 2012/110924 A1 and/or to WO2014/097181 A1. Thus, as outlined above, the at least one optical sensormay comprise at least one longitudinal optical sensor and/or at leastone transversal optical sensor, as described e.g. in WO 2014/097181 A1.Specifically, the at least one optical sensor may be or may comprise atleast one organic photodetector, such as at least one organic solarcell, more preferably a dye-sensitized solar cell, further preferably asolid dye sensitized solar cell, having a layer setup comprising atleast one first electrode, at least one n-semiconducting metal oxide, atleast one dye, at least one p-semiconducting organic material,preferably a solid p-semiconducting organic material, and at least onesecond electrode. For potential embodiments of this layer setup,reference may be made to one or more of the above-mentioned prior artdocuments.

The at least one optical sensor may be or may comprise at least onelarge-area optical sensor, having a single optically sensitive sensorarea. Still, additionally or alternatively, the at least one opticalsensor may as well be or may comprise at least one pixelated opticalsensor, having two or more sensitive sensor areas, i.e. two or moresensor pixels. Thus, the at least one optical sensor may comprise asensor matrix having two or more sensor pixels.

As outlined above, the at least one optical sensor may be or maycomprise at least one intransparent optical sensor. Additionally oralternatively, the at least one optical sensor may be or may comprise atleast one transparent or semitransparent optical sensor. Generally,however, in case one or more pixelated transparent optical sensors areused, in many devices known in the art, the combination of transparencyand pixelation imposes some technical challenges. Thus, generally,optical sensors known in the art both contain sensitive areas andappropriate driving electronics. Still, in this context, the problem ofgenerating transparent electronics generally remains unsolved.

As it turned out in the context of the present invention, it may bepreferable to split an active area of the at least one optical sensorinto an array of 2×N sensor pixels, with N being an integer, wherein,preferably, N≥1, such as N=1, N=2, N=3, N=4 or an integer >4. Thus,generally, the at least one optical sensor may comprise a matrix ofsensor pixels having 2×N sensor pixels, with N being an integer. Thematrix, as an example, may form two rows of sensor pixels, wherein, asan example, the sensor pixels of a first row are electrically contactedfrom a first side of the optical sensor and wherein the sensor pixels ofa second row are electrically contacted from a second side of theoptical sensor opposing the first side. In a further embodiment, thefirst and last pixels of the two rows of N pixels may further be splitup into pixels that are electrically contacted from the third and fourthside of the sensor. As an example, this would lead to a setup of 2×M+2×Npixels. Further embodiments are feasible.

In case two or more optical sensors are comprised in the opticaldetector, one, two or more optical sensors may comprise theabove-mentioned array of sensor pixels. Thus, in case a plurality ofoptical sensors is provided, one optical sensor, more than one opticalsensor or even all optical sensors may be pixelated optical sensors.Alternatively, one optical sensor, more than one optical sensor or evenall optical sensors may be non-pixelated optical sensors, i.e. largearea optical sensors.

In case the above-mentioned setup of the optical sensor is used,including at least one optical sensor having a layer setup comprising atleast one first electrode, at least one n-semiconducting metal oxide, atleast one dye, at least one p-semiconducting organic material,preferably a solid p-semiconducting organic material, and at least onesecond electrode, the use of a matrix of sensor pixels is specificallyadvantageous. As outlined above, these types of devices specifically mayexhibit the FiP-effect.

In these devices, such as FiP-devices, especially for SLM-based camerasas disclosed herein, a 2×N-array of sensor pixels is very well suited.Thus, generally, at least one first, transparent electrode and at leastone second electrode, with one or more layers sandwiched in between, apixelation into two or more sensor pixels specifically may be achievedby splitting one or both of the first electrode and the second electrodeinto an array of electrodes. As an example, for the transparentelectrode, such as a transparent electrode comprising fluorinated tinoxide and/or another transparent conductive oxide, preferably disposedon a transparent substrate, a pixelation may easily be achieved byappropriate patterning techniques, such as patterning by usinglithography and/or laser patterning. Thereby, the electrodes may easilybe split into an area of partial electrodes, wherein each partialelectrode forms a pixel electrode of a sensor pixel of the array ofsensor pixels. The remaining layers, as well as optionally the secondelectrode, may remain unpatterned, or may, alternatively, be patternedas well. In case a split transparent conductive oxide such asfluorinated tin oxide is used, in conjunction with unpatterned furtherlayers, cross conductivities in the remaining layers may generally beneglected, at least for dye-sensitized solar cells. Thus, generally, acrosstalk between the sensor pixels may be neglected. Each sensor pixelmay comprise a single counter electrode, such as a single silverelectrode.

Using at least one optical sensor having an array of sensor pixels,specifically a 2×N array, provides several advantages within the presentinvention, i.e. within one or more of the devices disclosed by thepresent invention. Thus, firstly, using the array may improve the signalquality. The modulator device of the optical detector may modulate eachpixel of the spatial light modulator, such as with a distinct modulationfrequency, thereby e.g. modulating each depth area with a distinctfrequency. At high frequencies, however, the signal of the at least oneoptical sensor, such as the at least one FiP-sensor, generallydecreases, thereby leading to a low signal strength. Therefore,generally, only a limited number of modulation frequencies may be usedin the modulator device. If the optical sensor, however, is split upinto sensor pixels, the number of possible depth points that can bedetected may be multiplied with the number of pixels. Thus, as anexample, two pixels may result in a doubling of the number of modulationfrequencies which may be detected and, thus, may result in a doubling ofthe number of pixels or superpixels of the SLM which may be modulatedand/or may result in a doubling of the number of depth points.

Further, as opposed to a conventional camera, the shape of the pixels isnot relevant for the appearance of the picture. Thus, generally, theshape and/or size of the sensor pixels may be chosen with no or littleconstraints, thereby allowing for choosing an appropriate design of thearray of sensor pixels.

Further, the sensor pixels generally may be chosen rather small. Thefrequency range which may generally be detected by a sensor pixel istypically increased by decreasing the size of the sensor pixel. Thefrequency range typically improves, when smaller sensors or sensorpixels are used. In a small sensor pixel, more frequencies may bedetected as compared to a large sensor pixel. Consequently, by usingsmaller sensor pixels, a larger number of depth points may be detectedas compared to using large pixels.

Summarizing the above-mentioned findings, the following embodiments arepreferred within the present invention:

Embodiment 1

A method of controlling pixels of at least one spatial light modulator,the spatial light modulator having a matrix of pixels, each pixel beingindividually controllable, the method comprising the following steps:

-   -   a) receiving at least one image;    -   b) defining at least one image segment within the image;    -   c) assigning at least one gray scale value to each image        segment;    -   d) assigning at least one pixel of the matrix of pixels to each        image segment;    -   e) assigning a unique modulation frequency to each gray scale        value assigned to the at least one image segment;    -   f) controlling the at least one pixel of the matrix of pixels        assigned to the at least one image segment with the unique        modulation frequency assigned to the respective image segment.

Embodiment 2

The method according to the preceding embodiment, wherein feasibleunique modulation frequencies for changing a state of the pixel aredetermined at least partially by using Walsh functions.

Embodiment 3

The method according to the preceding embodiment, wherein in step e) toeach gray scale value one Walsh function is assigned to the at least oneimage segment.

Embodiment 4

The method according to the preceding embodiment, wherein a plurality ofsegments is defined in step b), a set of Walsh functions is selected,taking into account the total number of functions needed and noisebetween used Walsh functions, wherein the total number of functionsneeded corresponds to the number of image segments defined.

Embodiment 5

The method according to any one of the preceding embodiments, wherein instep f) the at least one pixel is controlled with a Walsh function asunique modulation frequency.

Embodiment 6

The method according to the preceding embodiment, wherein a state of thepixel is switched according to a pattern given by the Walsh function.

Embodiment 7

The method according to the preceding embodiment, wherein step f)comprises the following substeps:

-   -   f1. assigning a counter threshold value to the unique modulation        frequency;    -   f2. incrementing a counter variable in a stepwise fashion at a        predetermined maximum frequency until the threshold value is        reached or exceeded;    -   f3. changing a state of the pixel.

Embodiment 8

The method according to the preceding embodiment, wherein thepredetermined maximum frequency is a maximum frequency f₀/2 for changingthe state of the pixel.

Embodiment 9

The method according to the preceding embodiment, wherein feasibleunique modulation frequencies f_(n) for changing the state of the pixelare determined by f_(n)=f₀/2n, wherein n is a nonzero integer number.

Embodiment 10

The method according to any one of the preceding embodiments, wherein atotal number of gray scale values depends on the total number of thefeasible unique frequencies.

Embodiment 11

The method according to any one of the preceding embodiments, whereineach pixel of the spatial light modulator has at least two states.

Embodiment 12

The method according to the preceding embodiment, wherein, in step f),the pixel is switched from a first state to a second state or viceversa.

Embodiment 13

The method according to any one of the preceding embodiments, whereingray scale values are color values and/or gray values.

Embodiment 14

The method according to any one of the preceding embodiments, whereinstep a) comprises providing a sequence of images.

Embodiment 15

The method according to the preceding embodiment, wherein steps b)-f)are repeated for each image of the sequence of images.

Embodiment 16

The method according to any one of two the preceding embodiments,wherein the sequence of images comprises a video.

Embodiment 17

The method according to any one of the preceding embodiments, whereinstep a) comprises providing the at least one image to a modulatordevice, wherein steps b)-f) are performed by the modulator device.

Embodiment 18

The method according to any one of the preceding embodiments, whereinstep a) comprises buffering the at least one image in at least one imagebuffer of the modulator device.

Embodiment 19

The method according to the preceding embodiment, wherein at least twoimage buffers are used.

Embodiment 20

The method according the preceding embodiment, wherein the image bufferscomprise a first image buffer and a second image buffer, wherein thefirst image buffer and the second image buffer are selected from thegroup consisting of an active image buffer and a non active imagebuffer.

Embodiment 21

The method according the preceding embodiment, wherein the at least oneimage is buffered in one or both of the non-active image buffer and theactive image buffer.

Embodiment 22

The method according the preceding embodiment, wherein the non-activeimage buffer is selected to further evaluate the at least one imagebuffered within the active image buffer, wherein at least a second imageis received and buffered in the active image buffer while evaluating theat least one image buffered within the active image buffer.

Embodiment 23

The method according to any one of the preceding embodiments, whereineach of the pixels comprises at least one micro-mirror.

Embodiment 24

A method of optical detection, specifically for determining a positionof at least one object, the method comprising the following steps:

-   -   modifying at least one property of a light beam in a spatially        resolved fashion by using at least one spatial light modulator,        the spatial light modulator having a matrix of pixels, each        pixel being controllable to individually modify the at least one        optical property of a portion of the light beam passing the        pixel, wherein the method of controlling pixels according to any        one of the preceding embodiments is used;    -   detecting the light beam after passing the matrix of pixels of        the spatial light modulator by using at least one optical sensor        and for generating at least one sensor signal;    -   periodically controlling at least two of the pixels with        different frequencies by using at least one modulator device;        and    -   performing a frequency analysis by using at least one evaluation        device and to determining signal components of the sensor signal        for the control frequencies.

Embodiment 25

A modulator device for controlling pixels of at least one spatial lightmodulator, the spatial light modulator having a matrix of pixels, eachpixel being individually controllable, the modulator device comprising:

-   -   a) at least one receiving device adapted for receiving at least        one image;    -   b) at least one image segment definition device adapted for        defining at least one image segment within the image;    -   c) at least one gray scale value assigning device adapted for        assigning at least one gray scale value to each image segment;    -   d) at least one pixel assigning device adapted for assigning at        least one pixel of the matrix of pixels to each image segment;    -   e) at least one frequency assigning device adapted for assigning        a unique modulation frequency to each gray scale value assigned        to the at least one image segment;    -   f) at least one controlling device adapted for controlling the        at least one pixel of the matrix of pixels assigned to the at        least one image segment with the unique modulation frequency        assigned to the respective image segment.

Embodiment 26

The modulator device according to the preceding embodiment, wherein themodulator device is adapted to perform a method according to any one ofthe preceding embodiments referring to a method of controlling pixels.

Embodiment 27

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the receiving device comprisesat least one buffer.

Embodiment 28

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the receiving device comprisesat least two image buffers.

Embodiment 29

The modulator device according the preceding embodiment, wherein theimage buffers comprise a first image buffer and a second image buffer,wherein the first image buffer and the second image buffer are selectedfrom the group consisting of an active image buffer and a non activeimage buffer.

Embodiment 30

The modulator device according the preceding embodiment, wherein thereceiving device is adapted to buffer the at least one image in one orboth of the non-active image buffer and the active image buffer.

Embodiment 31

The modulator device according the preceding embodiment, wherein thereceiving device is adapted to select the non-active image buffer tofurther evaluate the at least one image buffered within the active imagebuffer, wherein the receiving device is adapted to receive and buffer atleast a second image in the active image buffer while evaluating the atleast one image buffered within the active image buffer.

Embodiment 32

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein a frequency for receiving theat least one image is between 60 and 120 Hz.

Embodiment 33

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein one or more of the receivingdevice, the image segment definition device, the gray scale valueassigning device, the pixel assigning device and the frequency assigningdevice are fully or partially comprised by one or more of: a memorydevice, a processor, a programmable logic such as an FPGA, DLPC, CPLD,ASIC or VLSI-1C.

Embodiment 34

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the controlling devicecomprises at least one oscillator.

Embodiment 35

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the modulator device is adaptedsuch that each of the pixels is controlled at a unique frequency.

Embodiment 36

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the modulator device is adaptedfor periodically modulating the at least two pixels with differentunique modulation frequencies.

Embodiment 37

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the controlling device isadapted to assign a counter threshold value to the unique modulationfrequency, wherein the controlling device is further adapted toincrement a counter variable in a stepwise fashion at a predeterminedmaximum frequency until the threshold value is reached or exceeded andto change a state of the pixel.

Embodiment 38

The modulator device according to the preceding embodiment, wherein thepredetermined maximum frequency is a maximum frequency f₀ for changingthe state of the pixel resulting in f₀/2 for the pixel area in the lightbeam.

Embodiment 39

The modulator device according to the preceding embodiment, whereinfeasible unique modulation frequencies f_(n) for changing the state ofthe pixel are determined by f_(n)=f₀/2n, wherein n is a nonzero integernumber.

Embodiment 40

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the spatial light modulator isa bipolar spatial light modulator, wherein each pixel has at least twostates.

Embodiment 41

The modulator device according to the preceding embodiment, wherein thecontrolling device is adapted to switch the pixel from a first state toa second state or vice versa.

Embodiment 42

The modulator device according to any one of the preceding embodimentsreferring to a modulator device, wherein the receiving device is adaptedto receive a sequence of images.

Embodiment 43

A modulator assembly for spatial light modulation, the modulatorassembly comprising at least one spatial light modulator and at leastone modulator device according to any one of the preceding embodimentsreferring to a modulator device.

Embodiment 44

The modulator assembly according to the preceding embodiment, whereinthe at least one spatial light modulator is adapted to modify at leastone property of a light beam in a spatially resolved fashion, thespatial light modulator having a matrix of pixels, each pixel beingcontrollable to individually modify at least one optical property of aportion of the light beam passing the pixel, wherein the at least onemodulator device is adapted for periodically controlling at least two ofthe pixels with different unique modulation frequencies.

Embodiment 45

An optical detector comprising:

-   -   at least one modulator assembly according to any one of the        preceding embodiments referring to a modulator assembly;    -   at least one optical sensor adapted to detect the light beam        after passing the matrix of pixels of the spatial light        modulator and to generate at least one sensor signal; and    -   at least one evaluation device adapted for performing a        frequency analysis in order to determine signal components of        the sensor signal for unique modulation frequencies.

Embodiment 46

The optical detector according to the preceding embodiment, wherein theevaluation device is further adapted to assign each signal component toa respective pixel in accordance with its modulation frequency.

Embodiment 47

The optical detector according to any one of the preceding embodiments,wherein the modulator device is adapted such that each of the pixels iscontrolled at a unique modulation frequency.

Embodiment 48

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the evaluation device isadapted for performing the frequency analysis by demodulating the sensorsignal with different modulation frequencies.

Embodiment 49

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one property ofthe light beam modified by the spatial light modulator in a spatiallyresolved fashion is at least one property selected from the groupconsisting of: an intensity of the portion of the light beam; a phase ofthe portion of the light beam; a spectral property of the portion of thelight beam, preferably a color; a polarization of the portion of thelight beam; a direction of propagation of the portion of the light beam.

Embodiment 50

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one spatial lightmodulator comprises at least one spatial light modulator selected fromthe group consisting of: a transmissive spatial light modulator, whereinthe light beam passes through the matrix of pixels and wherein thepixels are adapted to modify the optical property for each portion ofthe light beam passing through the respective pixel in an individuallycontrollable fashion; a reflective spatial light modulator, wherein thepixels have individually controllable reflective properties and areadapted to individually change a direction of propagation for eachportion of the light beam being reflected by the respective pixel; anelectrochromic spatial light modulator, wherein the pixels havecontrollable spectral properties individually controllable by anelectric voltage applied to the respective pixel; an acousto-opticalspatial light modulator, wherein a birefringence of the pixels iscontrollable by acoustic waves; an electro-optical spatial lightmodulator, wherein a birefringence of the pixels is controllable byelectric fields.

Embodiment 51

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one spatial lightmodulator comprises at least one spatial light modulator selected fromthe group consisting of: a liquid crystal device, preferably an activematrix liquid crystal device, wherein the pixels are individuallycontrollable cells of the liquid crystal device; a micro-mirror device,wherein the pixels are micro-mirrors of the micro-mirror deviceindividually controllable with regard to an orientation of theirreflective surfaces; an electrochromic device, wherein the pixels arecells of the electrochromic device having spectral propertiesindividually controllable by an electric voltage applied to therespective cell; an acousto-optical device, wherein the pixels are cellsof the acousto-optical device having a birefringence individuallycontrollable by acoustic waves applied to the cells; an electro-opticaldevice, wherein the pixels are cells of the electro-optical devicehaving a birefringence individually controllable by electric fieldsapplied to the cells.

Embodiment 52

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the evaluation device isadapted to assign each of the signal components to a pixel of thematrix.

Embodiment 53

The optical detector according to any one of the preceding embodiments,wherein the evaluation device is adapted to assign each of the signalcomponents to a pixel of the matrix.

Embodiment 54

The optical detector according any one of the preceding embodiments,wherein the evaluation device is adapted to determine which pixels ofthe matrix are illuminated by the light beam by evaluating the signalcomponents.

Embodiment 55

The optical detector according to any of the preceding embodimentsreferring to an optical detector, wherein the evaluation device isadapted to identify at least one of a transversal position of the lightbeam and an orientation of the light beam, by identifying a transversalposition of pixels of the matrix illuminated by the light beam.

Embodiment 56

The optical detector according to the preceding embodiment, wherein theevaluation device is adapted to identify one or more of a transversalposition of an object from which the light beam propagates towards thedetector and a relative direction of an object from which the light beampropagates towards the detector, by evaluating at least one of thetransversal position of the light beam and the orientation of the lightbeam.

Embodiment 57

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the evaluation device isadapted to identify the signal components assigned to pixels beingilluminated by the light beam and to determine the width of the lightbeam at the position of the spatial light modulator from known geometricproperties of the arrangement of the pixels.

Embodiment 58

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the evaluation device, using aknown or determinable relationship between a longitudinal coordinate ofan object from which the light beam propagates towards the detector andone or both of a width of the light beam at the position of the spatiallight modulator or a number of pixels of the spatial light modulatorilluminated by the light beam, is adapted to determine a longitudinalcoordinate of the object.

Embodiment 59

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the capability of the pixelsto modify the at least one optical property of the portion of the lightbeam passing the respective pixel is dependent on the spectralproperties of the light beam, specifically of the color of the lightbeam.

Embodiment 60

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one opticalsensor comprises at least one at least partially transparent opticalsensor such that the light beam at least partially may pass through thetransparent optical sensor.

Embodiment 61

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one opticalsensor comprises a stack of at least two optical sensors.

Embodiment 62

The optical detector according to the preceding embodiment, wherein atleast one of the optical sensors of the stack is an at least partiallytransparent optical sensor.

Embodiment 63

The optical detector according to any one of the two precedingembodiments, wherein at least one of the optical sensors of the stack isa pixelated optical sensor having a plurality of light-sensitive pixels.

Embodiment 64

The optical detector according to the preceding embodiment, wherein thepixelated optical sensor is an inorganic pixelated optical sensor,preferably a CCD chip or a CMOS chip.

Embodiment 65

The optical detector according to any one of the two precedingembodiments, wherein the pixilated optical sensor is a camera chip,preferably a full-color camera chip.

Embodiment 66

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one opticalsensor has at least one sensor region, wherein the sensor signal of theoptical sensor is dependent on an illumination of the sensor region bythe light beam, wherein the sensor signal, given the same total power ofthe illumination, is dependent on a width of the light beam in thesensor region, wherein the evaluation device preferably is adapted todetermine the width by evaluating the sensor signal.

Embodiment 67

The optical detector according to the preceding embodiment, wherein theat least one optical sensor contains at least two optical sensors,wherein the evaluation device is adapted to determine the widths of thelight beam in the sensor regions of the at least two optical sensors,wherein the evaluation device is further adapted to generate at leastone item of information on a longitudinal position of an object fromwhich the light beam propagates towards the optical detector, byevaluating the widths.

Embodiment 68

The optical detector according to any one of the two precedingembodiments, wherein the sensor signal of the optical sensor is furtherdependent on a modulation frequency of the light beam.

Embodiment 69

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the spatial light modulatorcomprises pixels of different colors, wherein the evaluation device isadapted to assign the signal components to the different colors.

Embodiment 70

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the spatial light modulator isa reflective spatial light modulator, wherein the optical sensorcomprises at least one transparent optical sensor, wherein the opticaldetector is set up such that the light beam passes through thetransparent optical sensor before reaching the spatial light modulator,wherein the spatial light modulator is adapted to at least partiallyreflect the light beam back towards the optical sensor.

Embodiment 71

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the optical detector containsat least one beam-splitting element adapted for dividing a beam path ofthe light beam into at least two partial beam paths.

Embodiment 72

The optical detector according to the preceding embodiment, wherein thebeam-splitting element comprises at least one element selected from thegroup consisting of: the spatial light modulator, a beam-splittingprism, a grating, a semi-transparent mirror, a dichroitic mirror.

Embodiment 73

The optical detector according to any one of the two precedingembodiments, wherein the beam-splitting element comprises the spatiallight modulator.

Embodiment 74

The optical detector according to the preceding embodiment, wherein thespatial light modulator is a reflective spatial light modulator.

Embodiment 75

The optical detector according to any one of the four precedingembodiments, wherein at least one optical sensor is located in each ofthe partial beam paths.

Embodiment 76

The optical detector according to the preceding embodiment, wherein atleast one stack of optical sensors is located in at least one of thepartial beam paths.

Embodiment 77

The optical detector according to any one of the two precedingembodiments, wherein at least one intransparent optical sensor islocated in at least one of the partial beam paths.

Embodiment 78

The optical detector according to the two preceding embodiments, whereinthe stack of optical sensors is located in a first one of the partialbeam paths and wherein the intransparent optical sensor is located in asecond one of the partial beam paths.

Embodiment 79

The optical detector according to the preceding embodiment, wherein thespatial light modulator is located in the first one of the partial beampaths.

Embodiment 80

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the optical detector comprisesat least one stack of optical sensors, wherein the optical detector isadapted to acquire a three-dimensional image of a scene within a fieldof view of the optical detector.

Embodiment 81

The optical detector according to the preceding embodiment, wherein theoptical sensors of the stack have differing spectral properties.

Embodiment 82

The optical detector according to the preceding embodiment, wherein thestack comprises at least one first optical sensor having a firstspectral sensitivity and at least one second optical sensor having asecond spectral sensitivity, wherein the first spectral sensitivity andthe second spectral sensitivity are different.

Embodiment 83

The optical detector according to any one of the two precedingembodiments, wherein the stack comprises optical sensors havingdiffering spectral properties in an alternating sequence.

Embodiment 84

The optical detector according to any one of the three precedingembodiments, wherein the optical detector is adapted to acquire amulticolor three-dimensional image, preferably a full-colorthree-dimensional image, by evaluating sensor signals of the opticalsensors having differing spectral properties.

Embodiment 85

The optical detector according to any one of the preceding embodiments,wherein the optical detector further comprises at least onetime-of-flight detector adapted for detecting at least one distancebetween the at least one object and the optical detector by performingat least one time-of-flight measurement.

Embodiment 86

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the optical detector furthercomprises at least one active distance sensor, having at least oneactive optical sensor adapted to generate a sensor signal whenilluminated by a light beam propagating from the object to the activeoptical sensor, wherein the sensor signal, given the same total power ofthe illumination, is dependent on a geometry of the illumination, theactive distance sensor further comprising at least one activeillumination source for illuminating the object.

Embodiment 87

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the spatial light modulatorcomprises at least one reflective spatial light modulator, wherein theoptical detector is further adapted to additionally use the reflectivespatial light modulator as a projector.

Embodiment 88

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the optical detector isadapted to detect, and preferably to track, at least one eye of acreature within a scene captured by the detector.

Embodiment 89

The optical detector according to the preceding embodiment, wherein theoptical detector is adapted to determine at least one longitudinalcoordinate of the at least one eye.

Embodiment 90

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the at least one opticalsensor comprises at least one array of sensor pixels, preferably anarray containing 2×N sensor pixels with N being an integer.

Embodiment 91

The optical detector according to any one of the preceding embodimentsreferring to an optical detector, wherein the optical detector,preferably the evaluation device, comprises at least one Walsh analyzeradapted to perform a Walsh analysis.

Embodiment 92

A detector system for determining a position of at least one object, thedetector system comprising at least one optical detector according toany one of the preceding embodiments referring to an optical detector,the detector system further comprising at least one beacon deviceadapted to direct at least one light beam towards the optical detector,wherein the beacon device is at least one of attachable to the object,holdable by the object and integratable into the object.

Embodiment 93

The detector system according to the preceding embodiment, wherein thebeacon device comprises at least one illumination source.

Embodiment 94

The detector system according to any one of the two precedingembodiments, wherein the beacon device comprises at least one reflectivedevice adapted to reflect a primary light beam generated by anillumination source independent from the object.

Embodiment 95

The detector system according to any one of the three precedingembodiments, wherein the detector system comprises at least two beacondevices, preferably at least three beacon devices.

Embodiment 96

The detector system according to any one of the four precedingembodiments, wherein the detector system further comprises the at leastone object.

Embodiment 97

The detector system according to the preceding embodiment, wherein theobject is a rigid object.

Embodiment 98

The detector system according to any of the two preceding embodiments,wherein the object is selected from the group consisting of: an articleof sports equipment, preferably an article selected from the groupconsisting of a racket, a club, a bat; an article of clothing; a hat; ashoe.

Embodiment 99

A human-machine interface for exchanging at least one item ofinformation between a user and a machine, wherein the human-machineinterface comprises at least one detector system according to any of thepreceding embodiments referring to a detector system, wherein the atleast one beacon device is adapted to be at least one of directly orindirectly attached to the user and held by the user, wherein thehuman-machine interface is designed to determine at least one positionof the user by means of the detector system, wherein the human-machineinterface is designed to assign to the position at least one item ofinformation.

Embodiment 99

An entertainment device for carrying out at least one entertainmentfunction, wherein the entertainment device comprises at least onehuman-machine interface according to the preceding embodiment, whereinthe entertainment device is designed to enable at least one item ofinformation to be input by a player by means of the human-machineinterface, wherein the entertainment device is designed to vary theentertainment function in accordance with the information.

Embodiment 100

A tracking system for tracking a position of at least one movableobject, the tracking system comprising at least one detector systemaccording to any of the preceding embodiments referring to a detectorsystem, the tracking system further comprising at least one trackcontroller, wherein the track controller is adapted to track a series ofpositions of the object at specific points in time.

Embodiment 101

A scanning system for determining at least one position of at least oneobject, the scanning system comprising at least one detector accordingto any of the preceding embodiments relating to a detector, the scanningsystem further comprising at least one illumination source adapted toemit at least one light beam configured for an illumination of at leastone dot located at at least one surface of the at least one object,wherein the scanning system is designed to generate at least one item ofinformation about the distance between the at least one dot and thescanning system by using the at least one detector.

Embodiment 102

A camera for imaging at least one object, the camera comprising at leastone optical detector according to any of the preceding embodimentsreferring to a detector.

Embodiment 103

A use of the optical detector according to any one of the precedingembodiments relating to an optical detector, for a purpose of use,selected from the group consisting of: a position measurement in traffictechnology; an entertainment application; a security application; ahuman-machine interface application; a tracking application; aphotography application; an imaging application or camera application; amapping application for generating maps of at least one space; a mobileapplication, specifically a mobile communication application; a webcam;a computer peripheral device; a gaming application; a camera or videoapplication; a security application; a surveillance application; anautomotive application; a transport application; a medical application;a sports application; a machine vision application; a vehicleapplication; an airplane application; a ship application; a spacecraftapplication; a building application; a construction application; acartography application; a manufacturing application; a use incombination with at least one time-of-flight detector; an application ina local positioning system; an application in a global positioningsystem; an application in a landmark-based positioning system; alogistics application; an application in an indoor navigation system; anapplication in an outdoor navigation system; an application in ahousehold application; a robot application; an application in anautomatic door opener; an application in a light communication system.

BRIEF DESCRIPTION OF THE FIGURES

Further optional details and features of the invention are evident fromthe description of preferred exemplary embodiments which follows inconjunction with the dependent claims. In this context, the particularfeatures may be implemented alone or in any reasonable combination. Theinvention is not restricted to the exemplary embodiments. The exemplaryembodiments are shown schematically in the figures. Identical referencenumerals in the individual figures refer to identical elements orelements with identical function, or elements which correspond to oneanother with regard to their functions.

In the figures:

FIG. 1 shows an exemplary embodiment of an optical detector according tothe present invention;

FIG. 2 shows an exemplary embodiment of a demodulator which may be partof an evaluation device adapted for frequency analysis in order todetermine signal components;

FIGS. 3 and 4 show alternative setups of an optical detector having atransparent spatial light modulator (FIG. 3) and a reflective spatiallight modulator (FIG. 4);

FIG. 5 shows an exemplary embodiment of an optical detector adapted for3D imaging;

FIG. 6 shows an exemplary embodiment of an optical detector for colorrecognition;

FIG. 7 shows an exemplary embodiment of phase separation of colorsignals in the setup of FIG. 6;

FIG. 8 shows an exemplary embodiment of an optical detector used in ahuman-machine interface, a detector system, an entertainment device anda tracking system;

FIGS. 9-11 show alternative setups of the optical detector;

FIG. 12 shows potential application positions of the optical detector ina vehicle;

FIG. 13 shows a setup of an embodiment of the optical detector adaptedfar defining superpixels;

FIG. 14 shows a flow diagram of a method for detecting an object byusing the optical detector of FIG. 13;

FIGS. 15 and 16 show embodiments of object following;

FIG. 17 shows an embodiment of a cross-shaped setup of an opticaldetector having to beam splitters;

FIG. 18 shows an alternative embodiment of a W-shaped setup of anoptical detector;

FIG. 19 shows an arrangement of the optical detector to be used as alight-field camera;

FIG. 20 shows an exemplary arrangement of a stack of colored opticalsensors for use in the setup of FIG. 19;

FIG. 21 shows an exemplary arrangement of an implementation of atime-of-flight detector into the optical detector;

FIGS. 22 and 23 show alternative embodiments of the W-shaped setup ofthe optical detector of FIG. 18;

FIG. 24 shows an embodiment of an optical sensor comprising an array of2×4 sensor pixels;

FIG. 25 shows a setup of an embodiment of the optical detectorcomprising at least one modulator assembly;

FIG. 26 A shows an embodiment of at least one image;

FIG. 26 B shows an embodiment of a blinking pattern generated by aspatial light modulator;

FIG. 27 shows an exemplary embodiment of the method of controllingpixels of at least one spatial light modulator;

FIGS. 28 A and B show exemplary embodiments of frequency generation;

FIG. 28 C shows an embodiment of time dependency of counter variables;

FIGS. 29 A to H show selected Walsh functions;

FIG. 30 A shows reconstruction quality using Walsh transformation;

FIG. 30 B shows a comparison of the reconstruction quality for Walshtransformation and for Fourier transformation; and

FIG. 31 shows an effect of filtering processes on signal reconstruction.

EXEMPLARY EMBODIMENTS

In FIG. 1, an exemplary embodiment of an optical detector 110 and of adetector system 112 is disclosed. The optical detector 110 comprises atleast one spatial light modulator 114, at least one optical sensor 116,at least one modulator device 118 and at least one evaluation device120. The detector system 112, besides the at least optical detector 110,comprises at least one beacon device 122 which is at least one ofattachable to an object 124, holdable by the object 124 and integratableinto the object 124. The optical detector 110, in this embodiment,furthermore may comprise one or more transfer devices 126, such as oneor more lenses, preferably one or more camera lenses. In the exemplaryembodiment shown in FIG. 1, the spatial light modulator 114, the opticalsensor 116 and the transfer device 126 are arranged along an opticalaxis 128 in a stacked fashion. The optical axis 128 defines alongitudinal axis or z-axis, wherein a plane perpendicular to theoptical axis 128 defines a x-y-plane. Thus, in FIG. 1, a coordinatesystem 130 is shown, which may be a coordinate system of the opticaldetector 110 and in which, fully or partially, at least one item ofinformation regarding a position and/or orientation of the object 124may be determined.

The spatial light modulator 114 in the exemplary embodiment shown inFIG. 1 may be a transparent spatial light modulator, as shown, or may bean intransparent, such as a reflective, spatial light modulator 114. Forfurther details, reference may be made to the potential embodimentsdiscussed above. The spatial light modulator comprises a matrix 132 ofpixels 134 which preferably are individually controllable toindividually modify at least one optical property of a portion of alight beam 136 passing the respective pixel 134. In the exemplary andschematic embodiment shown in FIG. 1, the light beam is denoted byreference number 136 and may be emitted and/or reflected by the one ormore beacon devices 122. As an example, the pixels 134 may be switchedbetween a transparent state or an intransparent state and/or atransmission of the pixels may be switched between two or moretransparent states. In case a reflective and/or any other type ofspatial light modulator 114 is used, other types of optical propertiesmay be switched. In the embodiment shown in FIG. 1, four pixels areilluminated, such that the light beam 136 is split into four portions,each of the portions passing through a different pixel 134. Thus, theoptical property of the portions of the light beam may be controlledindividually by controlling the state of the respective pixels.

The modulator device 118 is adapted to individually control the pixels134, preferably all of the pixels 134, of the matrix 132. Thus, as shownin the exemplary embodiment of FIG. 1, the pixels 134 may be controlledat different unique modulation frequencies, which, for the sake ofsimplicity, are denoted by the position of the respective pixel 134 inthe matrix 132. Thus, unique modulation frequencies f₁₁ to f_(mn) areprovided for an m×n matrix 132. As outlined above, the term “uniquemodulation frequency” may refer to the fact that one or more of theactual frequency and the phase of the unique modulation may becontrolled.

Having passed the spatial light modulator 114, the light beam 136, nowbeing influenced by the spatial light modulator 114, reaches the one ormore optical sensors 116. Preferably, the at least one optical sensor116 may be or may comprise a large-area optical sensor having a singleand uniform sensor region 138. Due to the beam propagation properties, abeam width w will vary, when the light beam 136 propagates along theoptical axis 128.

The at least one optical sensor 116 generates at least one sensor signalS, which, in the embodiment shown in FIG. 1, is denoted by S₁ and S₂. Atleast one of the sensor signals (in the embodiment shown in FIG. 1 thesensor Signal S₁) is provided to the evaluation device 120 and, therein,to a demodulation device 140. The demodulation device 140, which, as anexample, may contain one or more frequency mixers and/or one or morefrequency filters, such as a low pass filter, may be adapted to performa frequency analysis. As an example, the demodulation device 118 maycontain a lock-in device and/or a Fourier analyzer. The modulator device118 and/or a common frequency generator may further provide the uniquemodulation frequencies to the demodulation device 140. As a result, afrequency analysis may be provided which contains signal components ofthe at least one sensor signal for the unique modulation frequencies. InFIG. 1, the result of the frequency analysis symbolically is denoted byreference number 142. As an example, the result of the frequencyanalysis 142 may contain a histogram, in two or more dimensions,indicating signal components for each of the unique modulationfrequencies, i.e. for each of the frequencies and/or phases of themodulation.

The evaluation device 120, which may contain one or more data processingdevices 144 and/or one or more data memories 146, may further be adaptedto assign the signal components of the result 142 of the frequencyanalysis to their respective pixels 134, such as by a uniquerelationship between the respective unique modulation frequency and thepixels 134. Consequently, for each of the signal components, therespective pixel 134 may be determined, and the portion of the lightbeam 136 passing through the respective pixel 134 may be derived.

Thus, even though a large-area optical sensor 116 may be used, varioustypes of information may be derived from the frequency analysis, usingthe preferred unique relationship between the modulation of the pixels134 and the signal components.

Thus, as a first example, an information on a lateral position of theilluminated area or light spot 148 on the spatial light modulator 114may be determined (x-y-position). Thus, as symbolically shown in FIG. 1,significant signal components arise for unique modulation frequenciesf₂₃, f₁₄, f₁₃ and f₂₄. This exemplary embodiment allows for determiningthe positions of the illuminated pixels and the degree of illumination.In this embodiment, pixels 13, 14, 23 and 24 are illuminated. Since theposition of the pixels 134 in the matrix 132 generally is known, it maybe derived that the center of illumination is located somewhere inbetween these pixels, mainly within pixel 13. A more thorough analysisof the illumination may be performed, specifically if (which usually isthe case) a larger number of pixels 134 is illuminated. Thus, byidentifying the signal components having the highest amplitude, thecenter of illumination and/or a radius of the illumination and/or aspot-size or spot-shape of the light spot 148 may be determined. Thisoption of determining the transversal coordinates is generally denotedby x, y in FIG. 1. The option of determining a width of the light spot148 on the spatial light modulator 114 is symbolically depicted by w₀.

By determining a transversal or lateral position of the light spot 148on the spatial light modulator 114, using known imaging properties ofthe transfer device 126, a transversal coordinate of the object 124and/or of the at least one beacon device 122 may be determined. Thus, atleast one item of information regarding a transversal position of theobject 124 may be generated.

Further, since the beam width w₀ generally, at least if the beamproperties of the light beam 136 are known or may be determined (such asby using one or more beacon devices 122 emitting light beams 136 havingwell-defined propagation properties), the beam width w₀ may further beused, alone or in conjunction with beam waist w₁ and/or w₂ determined byusing the optical sensors 116, in order to determine a longitudinalcoordinate (z-coordinate) of the object 124 and/or the at least onebeacon device 122, as disclosed e.g. in WO 2012/110924 A1.

In addition or alternatively to the option of determining one or both ofat least one transversal coordinate x, y and/or determining at least onelongitudinal coordinate z, the information derived by the frequencyanalysis may further be used for deriving color information. Thus, aswill be outlined in further detail below, the pixels 134 may havediffering spectral properties, specifically different colors. Thus, asan example, the spatial light modulator 114 may be a multi-color or evenfull-color spatial light modulator 114. Thus, as an example, at leasttwo, preferably at least three different types of pixels 134 may beprovided, wherein each type of pixels 134 has a specific filtercharacteristic, having a high transmission e.g. in the red, the green orthe blue spectral range. As used herein, the term red spectral rangerefers to a spectral range of 600 to 780 nm, the green spectral rangerefers to a range of 490 to 600 nm, and the blue spectral range refersto a range of 380 nm to 490 nm. Other embodiments, such as embodimentsusing different spectral ranges, may be feasible.

By identifying the respective pixels 134 and assigning each of thesignal components to a specific pixel 134, the color components of thelight beam 136 may be determined. Thus, specifically by analyzing signalcomponents of neighboring pixels 134 having different transmissionspectra, assuming that the intensity of the light beam 136 on theseneighboring pixels is more or less identical, the color components ofthe light beam 136 may be determined. Thus, generally, the evaluationdevice 120, in this embodiment or other embodiments, may be adapted toderive at least one item of color information regarding the light beam136, such as by providing at least one wavelength and/or by providingcolor coordinates of the light beam 136, such as CIE-coordinates.

As outlined above, for determining at least one longitudinal coordinateof the object 124 and/or the at least one beacon device 122, arelationship between the width w of the beam and a longitudinalcoordinate may be used, such as the relationship of a Gaussian lightbeam as disclosed in formula (3) above. The formula assumes a focus ofthe light beam 136 at position z=0. From a shift of the focus, i.e. froma coordinate transformation along the z-axis, a longitudinal position ofthe object 128 may be derived.

In addition or alternatively to using the beam width w₀ at the positionof the spatial light modulator 114, a beam width w at the position ofthe at least one optical sensor 116 may be derived and/or used fordetermining the longitudinal position of the object 124 and/or thebeacon device 122. Thus, as outlined in further detail above, one ormore of the at least one optical sensors 116 may be a pixelated opticalsensor 116, allowing for a pixel count and, thus, similar to theequations given above, to allow for determining a number of illuminatedpixels and, thus, deriving a beam width thereof. Additionally oralternatively, at least one of the one or more optical sensors 116 maybe a FiP-sensor, as discussed above and as discussed in further detaile.g. in WO 2012/110924 A1. Thus, given the same total power ofillumination, the signal S may depend on the beam width w of therespective light spot 148 on the optical sensor 116. This effect may bepronounced by modulating the light beam 136, by the spatial lightmodulator 114 and/or any other modulation device. The modulation may bethe same modulation as provided by the modulator device 118 and/or maybe a different modulation, such as a modulation at higher frequencies.Thus, as an example, the emission and/or reflection of the at least onelight beam 136 by the at least one beacon device 122 may take place in amodulated way. Thus, as an example, the at least one beacon device 122may comprise at least one illumination source which may be modulatedindividually.

Due to the FiP-effect, the signal S₁ and/or S₂ may depend on a beamwidth w₁ or w₂, respectively. Thus, e.g. by using equation (3) givenabove, beam parameters of the light beam 136 may be derived, such as z₀and/or the origin of the z-axis (z=0). From these parameters, assymbolically depicted in FIG. 1, the longitudinal coordinate z of theobject 124 and/or of one or more of the beacon devices 122 may bederived.

In FIG. 2, symbolically, a setup of the modulator device 118 and of ademodulation device 140 is disclosed in a symbolic fashion, which allowsfor separating signal components (indicated by S₁₁ to S_(mn)) for thepixels 134 of the m×n matrix 132. Thus, the modulator device 118 may beadapted for generating a set of unique modulation frequencies f₁₁ tof_(mn), for the entire matrix 132 and/or for a part thereof. As outlinedabove, each of the unique modulation frequencies f₁₁ to f_(mn) mayinclude a respective frequency and/or a respective phase for the pixel134 indicated by the indices i, j, with i=1 . . . m and j=1 n. The setof frequencies f₁₁ to f_(mn) is both provided to the spatial lightmodulator 114, for modulating the pixels 134, and to the demodulationdevice 140. In the demodulation device 140, simultaneously orsubsequently, the unique modulation frequencies f₁₁ to f_(mn) are mixedwith the respective signal S to be analyzed, such as by using one ormore frequency mixers 150. The mixed signal, subsequently, may befiltered by one or more frequency filters, such as one or more low passfilters 152, preferably with well-defined cutoff frequencies. The setupcomprising the one or more frequency mixers 150 and the one or more lowpass filters 152 generally is used in lock-in analyzers and iswell-known to the skilled person.

By using the demodulation device 140, signal components to S₁₁ to S_(mn)may be derived, wherein each signal component is assigned to a specificpixel 134, according to its index. It shall be noted, however, thatother types of frequency analyzers may be used, such as Fourieranalyzers, and/or that one or more of the components shown in FIG. 2 maybe combined, such as by subsequently using one and the same frequencymixer 150 and/or one and the same low pass filter 152 for the differentchannels.

As outlined above, various setups of the optical detector 110 arepossible. Thus, as an example, the optical detector 110 as shown in FIG.1 may comprise one or more optical sensors 116. These optical sensors116 may be identical or different. Thus, as an example, one or morelarge-area optical sensors 116 may be used, providing a single sensitivearea 138. Additionally or alternatively, one or more pixelated opticalsensors 116 may be used. Further, in case a plurality of optical sensors116 is provided, the optical sensors 116 may provide identical ordifferent spectral properties, such as identical or different absorptionspectra. Further, in case a plurality of optical sensors 116 isprovided, one or more of the optical sensors 116 may be organic and/orone or more of the optical sensors 116 may be inorganic. A combinationof organic and inorganic optical sensors 116 may be used.

Thus, as an example, in FIG. 3, a schematic setup of an optical detector110 and a detector system 112 similar to the setup shown in FIG. 1 isgiven. While FIG. 1 shows the setup in a simplified perspective view,FIG. 3 shows the setup in a cross-sectional view of the detector 110.For most of the details of the detector 110, reference may be made tothe potential embodiments discussed above with regard to FIG. 1. Thecomponents of the optical detector 110 may fully or partially beembodied in one or more housings 154. Thus, the transfer device 126, thespatial light modulator 114, the at least one optical sensor 116 and theevaluation device 120 may be encased fully or partially within the samehousing 154 and/or may fully or partially be encased within separatehousings 154.

In the setup shown in FIG. 3, the spatial light modulator 114, again,may be a transparent spatial light modulator 114, which may be locatedbehind the transfer device 126, such as the lens. Further, the opticaldetector 110 may comprise one or more optical sensors 116 embodied aslarge-area optical sensors 156. Further, the at least one optical sensor116 may fully or partially be embodied as a transparent optical sensor158. Further, the at least one optical sensor 116 may fully or partiallybe embodied as an organic optical sensor 160, preferably a DSC or sDSC.Additionally or alternatively, at least one inorganic optical sensor 162may be provided, preferably a pixelated inorganic optical sensor and,more preferably, a CCD chip and/or a CMOS chip. Further, at least oneintransparent optical sensor 164 may be provided.

Thus, in case a plurality of optical sensors 116 is provided, theoptical sensors 116 may form a stack 166 of optical sensors 116, whereinat least one of the optical sensors 116 is fully or partially embodiedas an at least partially transparent optical sensor 158 and wherein atleast one of the optical sensors 116 is fully or partially embodied asan intransparent optical sensor 164. In the setup of the stack 166 shownin FIG. 3, as an example, on a side of the stack 166 furthest away fromthe spatial light modulator 114 and/or the object 124, an intransparentoptical sensor 164 is located, whereas in between the intransparentoptical sensor 164 and the spatial light modulator 114 one or moretransparent optical sensors 158 are located. This setup of the stack 166may easily be embodied by using one or more organic optical sensors 160as the transparent optical sensors 158, such as by using one or morelarge-area transparent DSCs or sDSCs, and by using an inorganic camerachip as the intransparent optical sensor 164, preferably a CCD and/orCMOS chip, preferably a full-color camera chip. Thus, the setup of theoptical detector 110 as shown in FIG. 3 may be an embodiment of a camera168 which may be used for taking 2D images by a pixelated optical sensor116, preferably the inorganic pixelated camera chip, at the far end ofthe stack 166, and, additionally, providing longitudinal information(z-information) by evaluating the signal components and/or the beamwidths, as discussed above with regard to FIG. 1. Thereby, a 3D camera168 may be realized, preferably a full-color 3D camera.

In FIG. 4, an alternative setup of the detector 110, the detector system112 and the camera 168 is shown. Thus, as discussed above, the spatiallight modulator 114 may be a transparent or intransparent spatial lightmodulator. Thus, as an example, spatial light modulators 114 based onliquid crystal technology may be used as transparent spatial lightmodulators 114. Alternatively, as shown in FIG. 4, micro-mirror devicesmay be used as reflective spatial light modulators 114, therebydeflecting the optical axis 128 and/or the light path. As an example,the reflective spatial light modulator 114 shown in FIG. 14 may have amatrix of pixels shaped as micro-mirrors either adapted to transmit therespective portion of the light beam 136 towards the stack 166 ofoptical sensors 116 and/or to block the respective portions, such as bydirecting these portions towards a beam dump 170 depicted in FIG. 4.Except for these modifications, the setup of the detector 110 and thecamera 168 of FIG. 4, including its optional variations, may beidentical to the setup disclosed with regard to FIG. 3.

In FIGS. 5 to 7, various functions of the setups of FIGS. 1 to 4, whichmay be realized in isolation or in any arbitrary combination, arerepeated. Thus, FIG. 5 shows a setup of the optical detector 110 as e.g.given in FIG. 3, indicating a combination of an intransparent opticalsensor 164 in a stack 166 with a plurality of transparent opticalsensors 158. Thus, the intransparent optical sensor 164 may be used forimaging, generating high-resolution images of an object 124 (not shown).The transparent optical sensors 158 of the stack 166 may be used, asoutlined above, for generating additional longitudinal positioninformation (z-information).

In the setup shown in FIG. 6, in conjunction with a pulse scheme shownin FIG. 7, color recognition is disclosed in further detail. Thus, aspatial light modulator 114 embodied as a full-color spatial lightmodulator 172 may be used, such as a transparent RGB TFT display withpixels. Further, one or more transparent, semitransparent orintransparent optical sensors 116 may be used, preferably large-areaoptical sensors 156, which may be able to provide signal components. Theevaluation device 120 (not shown) may be adapted to assign the signalcomponents to pixels 134 having different colors, by their uniquemodulation frequency, i.e. by their frequency and/or their phase. Theoption of phase separation symbolically is shown in FIG. 7. As can beseen therein, the signal components S may be separated according totheir phase, by red, green and blue (r, g, b) pixels emitting atdifferent times t, i.e. having differing phases φ₁, φ₂ and φ₃. Thus, byevaluating the signal components, color components of the light beam 136may be identified.

As outlined above, the optical detector 110, the detector system 112 andthe camera 168 may be used in various other devices and systems. Thus,the camera 168 may be used for imaging, specifically for 3D imaging, andmay be made for acquiring standstill images and/or image sequences suchas digital video clips. FIG. 8, as an exemplary embodiment, shows adetector system 112, comprising at least one optical detector 110, suchas the optical detector 110 as disclosed in one or more of theembodiments shown in FIGS. 1 through 6. In this regard, specificallywith regard to potential embodiments, reference may be made to thedisclosure given above. FIG. 8 further shows an exemplary embodiment ofa human-machine interface 174, which comprises the at least one detectorsystem 112, and, further, an exemplary embodiment of an entertainmentdevice 176 comprising the human-machine interface 174. The figurefurther shows an embodiment of a tracking system 178 adapted fortracking a position of at least one object 124, which comprises thedetector system 112.

The figure further shows an exemplary embodiment of a scanning system177 for determining at least one position of the at least one object124. The scanning system 177 comprises the at least one optical detector110 and, further, illumination source 179 adapted to emit at least onelight beam 136 configured for an illumination of at least one dot (e.g.a dot located on one or more of the positions of the beacon devices 122)located at at least one surface of the at least one object 124. Thescanning system 177 is designed to generate at least one item ofinformation about the distance between the at least one dot and thescanning system, specifically the detector 110, by using the at leastone optical detector.

With regard to the optical detector 110 and the detector system 112,reference may be made to the disclosure given above.

The evaluation device 120 may be connected to the optical sensors 116and the modulator device 118 and/or the spatial light modulator 112, byone or more connectors 180 and/or one or more interfaces. Further, theconnector 180 may comprise one or more drivers and/or one or moremeasurement devices for generating sensor signals. Further, theevaluation device 120 may fully or partially be integrated into theoptical sensors 116 and/or into the housing 154 and/or into the spatiallight modulator 114. Additionally or alternatively, the evaluationdevice 120 may fully or partially be designed as a separate, independentdevice.

In this exemplary embodiment shown in FIG. 8, the object 124 to bedetected may be designed as an article of sports equipment and/or or mayform a control element 182, the position and/or orientation of which maybe manipulated by a user 184. As an example, the object 124 may be ormay comprise a bat, a racket, a club or any other article of sportsequipment and/or fake sports equipment. Other types of objects 124 arepossible. Further, the user 184 himself or herself may be considered asthe object 124, the position of which shall be detected. As an example,the user 184 may carry one or more of the beacon devices 122 attacheddirectly or indirectly to his or her body.

As discussed above with regard to the potential options of FIG. 1, theoptical detector 110 may be adapted to determine one or more of atransversal position and a longitudinal position of one or more of thebeacon devices 122 and/or of the object 124. Additionally oralternatively, the optical detector 110 may be adapted for identifyingcolors and/or for imaging the object 124. An opening 186 inside thehousing 154, which, preferably, is located concentrically with regard tothe optical axis 128 of the detector 110, preferably defines a directionof view 188 of the optical detector 110.

The detector 110 may be adapted for determining a position of the atleast one object 124. Additionally, the optical detector 110 may beadapted for acquiring an image of the object 124, preferably a 3D image.

As outlined above, the determination of a position of the object 118and/or a part thereof by using the detector 110 and/or the detectorsystem 112 may be used for providing a human-machine interface 174, inorder to provide at least one item of information to a machine 190. Inthe embodiment schematically depicted in FIG. 8, the machine 190 may bea computer and/or may comprise a computer. Other embodiments arefeasible. The evaluation device 120 may be fully or partially embodiedas a separate device and/or may fully or partially be integrated intothe machine 180, such as into the computer. The same holds true for atrack controller 192, of the tracking system 178, which may fully orpartially form a part of the evaluation device 120 and/or the machine190.

Similarly, as outlined above, the human-machine interface 174 may formpart of an entertainment device 176. The machine 190, specifically thecomputer, may also form part of the entertainment device 176. Thus, bymeans of the user 184 functioning as the object 118 and/or by means ofthe user 184 handling the control element 182 functioning as the object124, the user 184 may input at least one item of information, such as atleast one control command, into the computer, thereby varying theentertainment function, such as controlling the course of a computergame.

As outlined above, the optical detector 110 may have a straight beampath, as e.g. in the setup of FIG. 3, or may be tilted, angulated,branched, deflected or split, such as in the rectangular setup shown inFIG. 4. Further, the light beam 136 may travel along each beam path orpartial beam path once or repeatedly, unidirectionally orbidirectionally. Thereby, the spatial light modulator 114 may fully orpartially be located in front of the at least one optical sensor 116and/or behind the at least one optical sensor 116.

In FIG. 9, an alternative setup of the optical detector 110 is shown,which may generally be used in the setup of FIG. 3. The modulator device118 and the evaluation device 120 as well as the object 124 and thebeacon devices 122 are not shown in the setup and may be embodied ase.g. shown in FIG. 3.

In the setup of FIG. 9, an incoming light beam 136 enters the opticaldetector 110 from the left, passes towards the right, passes the atleast one optional transfer device 126 such as the at least one lance,and passes a stack 166 of transparent optical sensors 158 for the firsttime, in an unmodulated fashion. Subsequently, the light beam 136 hitsthe spatial light modulator 114 and, as outlined above, is modulated bythe spatial light modulator 114. The spatial light modulator 114, inthis setup, is a reflective spatial light modulator adapted forreflecting the light beam 136 back towards the stack 166. Thus, thereflected light beam 136, traveling towards the left in FIG. 9, hits thestack 166 for the second time, thereby allowing for the above-mentionedz-detection of the object 124 and/or the beacon devices 122.

Further, as discussed above, the optical detector 110 may have a beampath which is split into a plurality of partial beam paths. A firstexemplary embodiment of a split beam path setup is shown in FIG. 10.Again, an optical detector 110 is shown, without the modulator device118 and the evaluation device 120 and without the object 124 and thebeacon devices 122, which may be embodied as e.g. shown in FIG. 3.

Again, the light beam 136 enters the optical detector 110 from the left,by passing the at least one optional transfer device 126. Subsequently,the light beam 136 hits the spatial light modulator 114, which, again,is embodied as a reflective spatial light modulator and which, in thiscase, is adapted to deflect the light beam 136 into a direction of afirst partial beam path 194 and into a direction of a second partialbeam path 196. Thus, as an example, the reflective spatial lightmodulator 114 may comprise, as discussed above, a matrix of pixelshaving micro-mirrors, wherein each micro-mirror may be adapted todeflect the incident light beam 136 either into the direction of thefirst partial beam path 194 or into the direction of the second partialbeam path 196. Thereby, the light beam 136 may be split into a firstpartial light beam 198 travelling along the first beam path 194, and asecond partial light beam 200 travelling along the second partial beampath 196.

Each one of the partial beam paths 194, 196 may define a coordinatesystem 130 of its own, wherein, since the setup of the optical detectoris known, these coordinate systems 130 of the partial beam paths 194,196 may be correlated to one another and/or may be correlated to acommon coordinate system 130 of the optical detector 110.

Within each one of the at least two partial beam paths 194, 196, one ormore optical elements may be located. Thus, in the setup shown in FIG.10, which may be called a W-shaped setup of the beam paths 164, 196, astack 196 of optical sensors 116 is located in the first partial beampath 194. Thus, the first partial beam path 194 may be dedicated toz-detection of the object 124. The second partial beam path 196 may bededicated to imaging, and, consequently, may contain one or moreinorganic optical sensors 162 and/or intransparent optical sensors 164,such as one or more camera chips. Thus, as an example, the secondpartial beam path may contain at least one pixelated imaging sensor,specifically in imaging sensor chip, such as at least one CCD- and/orCMOS-chip, preferably at least one full-color or RGB CCD- or CMOS-chip.

Further, optionally, one or more additional optical elements 202, 204may be located within the first partial beam path 194 and/or within thesecond partial beam path 196. Thus, as an example, the additionaloptical elements 202, 204 may be adapted for individually controlling anintensity and/or a focus and/or other optical properties of the partiallight beams 198, 200. Thus, as an example, one or more shutters and/orone or more attenuators such as one or more diaphragms may be presentfor individually controlling e.g. an intensity of the partial lightbeams 198, 200. Further, one or more lenses may be present within theadditional optical elements 202, 204.

In the setup of FIG. 10, the spatial light modulator 114 itself acts asa beam splitting element 206. Additionally or alternatively, other beamsplitting elements may be used for splitting a beam path 208 into atleast one first partial beam path 194 and at least one second beam path196. Thus, in FIG. 11, a setup of the optical detector is shown having abeam splitting element 206 being independent from the spatial lightmodulator 114. Again, as for FIGS. 9 and 10, the modulator device 118,the evaluation device 120, the object 124 and the beacon devices 122 arenot shown and may be embodied as e.g. shown in FIGS. 3 and/or 4.

Again, in FIG. 11, the light beam 136 enters the optical detector 110from the left, by passing the at least one transfer device 126,propagating along an optical axis and/or a beam path 208. Subsequently,by one or more beam splitting elements 206 such as one or more prisms,one or more semi-transparent mirrors or one or more dichroitic mirrors,the light beam 136 is split into a first partial light beam 198travelling along a first partial beam path 194, and a second partiallight beam 200, propagating along a second partial beam path 196. Inthis embodiment, the spatial light modulator is depicted as a reflectivespatial light modulator, deflecting the first partial light beam 198towards the stack of optical sensors 116. Alternatively, however, atransparent spatial light modulator 114 may be used, as in the setup ofFIG. 3, thereby rendering the first partial beam path 194 straight.Alternatively, again, the setup as shown in FIG. 9 may be used for thefirst partial beam path 194.

As in the setup of FIG. 10, in the second partial beam path 196, atleast one intransparent optical sensor 164 may be located, such as animaging sensor, more preferably a CCD- and/or

CMOS-chip, more preferably a full-color or RGB CCD- or CMOS chip. Thus,as in the setup of FIG. 10, the second partial beam path 196 may bededicated to imaging and/or determining x- and/or y-coordinates, whereasthe first partial beam path 194 may be dedicated to determining az-coordinate, wherein, still, in this embodiment or other embodiments,an x-y-detector may be present in the first partial beam path 194.Again, as in the setup of FIG. 10, individual additional opticalelements 202, 204 may be present within the partial beam paths, 194,196.

In FIG. 12, potential application positions of the optical detector 110and/or the detector system 112 according to the present invention inautomotive systems are shown. For potential applications, reference maybe made to the disclosure given above.

Thus, in FIG. 12, as an exemplary embodiment of potential uses inautomotive systems, a car 210 is shown in a simplified perspective view.Therein, various potential positions of optical detectors 110 and/ordetectors systems 112 are shown, which may be used individually or inany arbitrary combination.

Thus, one or more optical detectors 110 may be used in the region of awindshield 212 of the car 210, such as in various positions surroundingthe windshield 212 and/or even within the windshield 212, such as foruse as rain sensors.

Further, one or more optical detectors 110 in the region of a front part214 of car 210 may be present. These optical detectors 110 may be usedas sensors in headlights 216 and/or bumpers 218. Similarly, which is notshown, one or more optical detectors 110 may be present in the rearbumpers and/or as sensors in the backlights. Thus, one or more of theoptical detectors 110 may be used as distance sensors and/or for otherassistance applications, such as one or more of the applications listedabove. Thus, as an example, lane departure warning may be named as apotential application of one or more of the optical detectors 110.

Further, one or more optical detectors 110 may be present in the sideregion 220 of car 210. Thus, one or more optical detectors may bepresent at or near passenger doors 222, such as in order to avoidcollisions of the doors with a solid objects.

Further, one or more optical detectors 110 may be present on a roof 224of the car 210 and/or at a rear part 226. Thus, similar to the sensorsin the front part 214, one or more optical detectors 110 in the rearpart 226 may be used as a distance sensor, such as for parkingassistance.

In FIGS. 13 and 14, a further embodiment of the present invention isshown which makes use of subdividing the matrix 132 of pixels 134 of thespatial light modulator 114 into superpixels. Therein, FIG. 13 shows asetup of the optical detector 110, whereas FIG. 14 shows a flow of amethod for using the optical detector 110 and of a method of opticaldetection. Both figures will be explained in the following.

In this exemplary embodiment, the optical detector 110 is generallysetup, in terms of hardware, as in the exemplary embodiment shown inFIG. 10. Thus, for details of the setup, reference may be made to thedescription of FIG. 10 above. Thus, a split beam path is used in thesetup, specifically a W-shaped setup. Still, it shall be noted thatother setups are feasible, such as the split beam path setup shown inFIG. 11 or the non-split beam path setup is shown in the embodiments ofFIG. 3, 4 or 9.

As outlined above, the optical detector 110 comprises the stack 166 ofoptical sensors 116 which, individually or in common, act as at leastone FiP-sensor 228 for z-detection, i.e. for determining at least onez-coordinate of at least one object 124. In this embodiment, stack 166is arranged in the first partial beam path 194. Further, the opticaldetector 110 comprises, for example in the second beam path 196, animage sensor 230, which may be a pixelated optical sensor 116 and whichmay also be referred to as an image detector or an imaging device. As anexample and as outlined above, image sensor 230 may be or may compriseone or more CCD and/or CMOS sensors, such as monochrome CCD and/or CMOSsensors, multi-chrome CCD and/or CMOS sensors or full-color CCD and/orCMOS sensors. Thus, by using the at least one FiP-sensor 228, adetermination of at least one longitudinal coordinate or z-coordinate ofat least one object 124 detected by the optical detector 110 ispossible, whereas, by using the at least one image sensor 228, a 2Dimaging of the at least one object 124 is possible.

In the exemplary setup shown in FIG. 13, a scene comprising two objects,denoted by O₁ and O₂, is captured by the optical detector 110. As can beseen in FIG. 14, in a first method step 232, a 2D image 234 of the sceneis captured by using the at least one image sensor 228. In a subsequentmethod step, referred to as method step 236 in FIG. 14, two or moreregions are detected in the 2D image 234. Thus, corresponding to objectsO₁ and O₂ in FIG. 13, two or more regions may be defined in the 2D image234, which are denoted by R₁ and R₂. Further, optionally, a backgroundregion may be defined, denoted by R₀. The regions may be defined bydetermining their respective transversal coordinates or coordinateranges in the 2D image 234, as symbolically denoted by x₁, y₁, x₂, y₂ inFIG. 13 or by x, y in step 236 of FIG. 14. Consequently, image sensor230 may act as a transversal optical sensor. For potential techniques ofdefining the regions, reference may be made to the above-mentionedalgorithms. As an example, boundaries of regions R₁ and R₂ may bedetected by detecting gradients of intensity or color. As depicted inFIG. 13, the detection of the regions may take place within the at leastone evaluation device 120, which may provide at least one dataprocessing device with an appropriate software for image recognitionand/or image analysis.

In a further step, denoted by reference number 238 in FIG. 14,superpixels are assigned to the regions. For this purpose, pixels 134 ofthe spatial light modulator 114 are defined which correspond to regionsR₀, R₁ and R₂ in the 2D image 234. Thus, due to known transmissionproperties, it is generally known or may generally be determined whichcomponents of the light beam 136 or partial light beam 200 pass whichpixels 134 before hitting corresponding pixels of the image sensor 230.Consequently, a known or determinable relationship, which, e.g. may be acalculated analytical relationship or an empirical or semi-empiricallyrelationship, between pixels of the spatial light modulator 114 and theimage sensor 230 may be used.

By defining superpixels, in FIG. 13 referred to as S₀, S₁ and S₂, uniquemodulation frequencies may be assigned to the corresponding superpixels,as denoted by f₀, f₁ and f₂ in FIG. 13. The step of assigning uniquemodulation frequencies to the superpixels is denoted by reference number240 in FIG. 14. Subsequently (step 242 in FIG. 14), the superpixels aremodulated with their corresponding unique modulation frequencies.Consequently, each pixel 134 of a superpixel is modulated with thecorresponding unique modulation frequency assigned to the respectivesuperpixels. Further, sub-modulations, i.e. subdivisions of eachsuperpixels and assigning additional modulations to the subdivisions,are possible.

Further, in step 244 in FIG. 14, a z-detection of one or more than oneor even all of the superpixels takes place. For this purpose, the atleast one optical sensor 116 acting as a FiP-sensor 228 is used, whichmay also be referred to as a longitudinal optical sensor since alongitudinal coordinate is determined by using this optical sensor.Thus, as an example and as shown in FIG. 13, the stack 166 may be used.The at least one signal of the stack 166 is demodulated in afrequency-selective way, by using f₀, f₁ and f₂ as demodulationfrequencies and by individually evaluating the signal componentscorresponding to these demodulation frequencies, in order to determinethe z-coordinates. Thus, for example, z-coordinates z₁ and z₂ may bedetermined for objects O₁ and O₂. Thereby (step 246 in FIG. 14), a 3Dimage of the scene captured by the optical detector 110 or a part ofthis scene, such as of one or more of the objects 124 comprise therein,may be generated, by combining the transversal coordinates generated instep 236 with the longitudinal coordinates determined in step 244. Thus,as an example, for each object 124 or for one or more of objects 124comprised within a scene, transversal coordinates or coordinate rangesx₁, y₁, x₂, y₂ may be combined with corresponding z-coordinates z₁ andz₂, thereby generating 3D coordinates (x₁, y₁, z₁) and (x₂, y₂, z₂) ofobjects O₁ and O₂. Again, steps 244 and/or 246 may be performed by theat least one evaluation device 120.

As will be evident to the skilled person, the setup and scheme shown inFIGS. 13 and 14 simply denotes a simplified way of 3D imaging. Morecomplex scenes may be captured by the optical detector 110. Further,more complex objects 124 as schematically depicted in FIG. 13 may beused, such as objects 124 which, in itself, comprise a plurality ofparts or components. These parts are components of the at least oneobject 112 themselves may be regarded as objects 112 and, consequently,their 2D images may be defined as separate regions in the 2D image 234.Consequently, separate superpixels may be assigned to these objectparts.

Further, as symbolically depicted by reference number 248 in FIG. 14,the procedure shown in FIG. 14, the procedure, as a whole or partly, maybe performed iteratively. Thus, as an example, a refining of the regionsand/or superpixels may take place, such as in case a large range ofz-coordinates is detected in step 244 within one superpixel. Thus,detecting a large range of z-coordinates for one region and/orsuperpixel may indicate that a corresponding object 124 has a depthalong a z-axis. Consequently, the corresponding region and/or superpixelmay be refined or subdivided into a plurality of regions and/orsuperpixels. As an example, region R₂ corresponding to spherical objectO₂ may be subdivided into two or more concentric annular regions inorder to fully recognize the depth of this spherical object. Thisrefining 248 may take place for one or more of the object or componentscontained within a scene or for the full scene. Thereby, the detectionprocedure may start with a simplified setup and with a simplifiedapproach, such as with a few regions and/or superpixels, followed by oneor more iterations for refining the findings and for obtaining moredetailed information for one, more than one or even all objectscontained within the scene.

In FIGS. 15 and 16, the principle of object following, as possible withthe optical detector 110 according to the present invention, shall beexplained. Thus, by using an image sensor 230 such as in a setup asexplained with reference to FIG. 13, an image 234 is taken. In theexemplary embodiment shown in FIG. 15, the image may be the image of ahuman head or face. In the embodiment shown in FIG. 16, the image may bea scene in traffic, such as in a field of view of a front camera in avehicle on a motorway.

Within the image 234, by using appropriate image recognition algorithmsand/or by using a specific training, one or more objects may berecognized. As an example, eyes may be recognized, marked by O₁ and O₂in FIG. 15. Similarly, a facial region may be recognized, marked by O₃in FIG. 15. In the traffic scene of FIG. 16, various vehicles O₄-O₆ maybe recognized. Additionally or alternatively, road signs O₇, O₈ may berecognized, such as road signs indicating speed limits and/or indicatingdistances to various cities along the road. These objects O₁-O₈ each maybe assigned corresponding regions R₁-R₈, in the images 234, wherein theregions might be simplified geometric patterns of various shapes withinthe images 234, such as boxes, rectangles or squares.

As explained above with reference to FIG. 13, each of these regionsR₁-R₈ may be assigned to corresponding superpixels of the spatial lightmodulator 114. Consequently, instead of analyzing the entire image 234,image analysis may be reduced to a following or tracking of objectsO₁-O₈. For this purpose, the superpixels corresponding to the regionsR₁-R₈ may be tracked by retrieving z-coordinates for the at least onefrequency assigned to the at least one region or, in this embodiment,regions R₁-R₈, only. For each of the objects, a distance may thus bedetermined. In a series of images such as an ongoing camera moviecapturing a scene, in each image or in a plurality of the images, theone or more objects of interest may be detected, followed by assigningone or more superpixels to these objects and determining z-coordinatesand/or distances for these objects only, by using the longitudinaloptical sensor, specifically the FiP-sensor 228.

In FIGS. 17 and 18, alternative setups of the optical detector 110and/or the camera 168 are shown. Again, as for the setup in FIG. 11, anincoming light beam 136 is split up into a plurality of partial lightbeams. In the embodiment of FIG. 17, an optical detector 110 is shownwhich may also serve as an exemplary embodiment of a camera 168. Anincoming light beam 136, traveling along an optical axis 128 of theoptical detector 110, hits a first beam-splitting element 250 which isadapted to separate a first partial light beam 252 from a main lightbeam 254. The first partial light beam 252 may have an intensitysignificantly lower as compared to the main light beam 254, since thefirst partial light beam 252 serves the purpose of observation of anobject, from which the light beam 136 originates, by an imaging device256, such as a CCD and/or CMOS chip, as in the embodiment of FIG. 11. Asan example, the first partial light beam 252 may have an intensity ofless than one half of the main light beam 254. As an example, the firstbeam-splitting element 250 may divide the incoming light beam 136 by aratio of 10 to 90. For this purpose, the transparency of the firstbeam-splitting element 250 may be adjusted and/or an overall surfacearea of the first beam-splitting element may be adjusted.

The first partial light beam 252 may be modified by various opticalelements. As an example, in a first partial beam path 258, between thefirst beam-splitting element 250 and the imaging device 256, at leastone diaphragm 260 and/or at least one transfer device 126, such as atleast one lens system 262, may be located. Other embodiments arefeasible.

The main light beam 254 continues traveling along the optical axis 128and meets a second beam-splitting element 264. As an example, the secondbeam-splitting element 264 may be or may comprise a beam-splitter cube,preferably a polarizing beam-splitter cube. The second beam-splittingelement 264 splits up the main light beam 254 into a second partiallight beam 266 traveling along a second partial beam path 268 and athird partial light beam 270 traveling along a third partial beam path272. The second partial light beam 266 hits a first spatial lightmodulator 114, referred to as SLM 1 or DLP 1 in FIG. 17. Similarly, thethird partial light beam 270 hits a second spatial modulator 114,referred to as SLM 2 or DLP 2 in FIG. 17. The first and second spatiallight modulators, in this specific embodiment, specifically may bereflective spatial light modulators, specifically reflective spatiallight modulators based on the DLP® technology. Other types of spatiallight modulators are feasible. By the first and second spatial lightmodulators, the second and third partial light beams 266 and 270 areback-reflected along the second and third partial beam path 268 and 272,respectively, to form back-reflected partial light beams 274 and 276. Inthe second beam-splitting element 264, the back-reflected partial lightbeams 274, 276 are re-united to form a common light beam 278 travelingalong a fourth partial beam path 280 towards a stack 166 of opticalsensors 116, which may act as a longitudinal optical sensor fordetermining a z-coordinate of an object from which the light beam 136travels towards the optical detector 110.

Before being re-united to form the common light beam 278, the partiallight beams 266, 270 may be subject to various operations. Thus,generally, the partial light beam 266 may have a polarizationperpendicular to the plane of view of FIG. 17. By using a firsthalf-wave-plate 282, the polarization of partial light beam 266 may beturned into the plane of view of FIG. 17. The back-reflection by SLM 1may, again, turn the direction of polarization of this partial lightbeam 266, such that back-reflected partial light beam 274 may, again,have a polarization perpendicular to the plane of view in FIG. 17. Thefirst half-wave-plate 282, however, again, turns polarization into theplane of view of FIG. 17, thereby allowing a transmission of theback-reflected partial light beam 274 towards the stack 166.

Similarly, the third partial light beam 270, after passing thepolarization beam splitter cube 264, has a polarization parallel to theplane of view of FIG. 17. After passing second half-wave-plate 284,after back-reflection at SLM 2 and after, again, passing the secondhalf-wave-plate 284, the back-reflected third partial light beam 276 hasa polarization perpendicular to the plane of view in FIG. 17 and,consequently, is deflected by the second beam-splitting element 264towards the stack 166. Thus, back-reflected partial light beams 274, 276are both deflected towards stack 166 and may form the common light beam278.

Further, various types of transfer devices 126 may be located within thesecond and third partial beam path 268 and 272, such as one or morelenses, as depicted in FIG. 17. Other embodiments are feasible.

The first and second spatial light modulators SLM 1, SLM 2 may beadapted to modulate partial light beams 266, 270, in the same way or ina different way. Thus, generally, in case a plurality of spatial lightmodulators 114 is used, as e.g. in the embodiment of FIG. 17, theplurality of spatial light modulators 114 may be driven in asynchronized way. However, other modes of operation are feasible.

The setup as shown in FIG. 17 implies various advantages. Thus, thesetup generally makes use of the fact that, typically, less light isneeded for imaging device 256, as compared e.g. to the detection of thez-coordinate by using the FiP-sensor. Thus, by using the firstbeam-splitting element 250, 10% or a similar energy or intensity of theincoming light beam 136 may be separated off, for the purpose of theimaging device 256. 90% or a similar, larger amount of the incominglight beam 136 may continue towards the longitudinal optical sensor,such as the FiP.

Typically, a picture of the object from which light beam 136 travelstowards the optical detector 110, should be in focus with the spatiallight modulators SLM 1, SLM 2. However, most commercial versions ofreflective spatial light modulators, such as DLP® chips, are generallynot designed for a straight back-reflection but for a back-reflectionunder a certain angle. Therefore, it might be necessary to useasymmetrical lens systems allowing for an in-focus picture on each ofthe spatial light modulators SLM 1, SLM 2, which are not perpendicularto the optical axis. These options, however, shall be included whenreferring to a “back reflection”.

It shall be noted that the various ideas shown in the embodiment of FIG.17 may be combined in an arbitrary fashion. Thus, generally, the idea ofsplitting off a minor part of the incoming light beam 136 for thepurpose of imaging by at least one imaging device 256 may be usedindependently from the idea of using a plurality of spatial lightmodulators 114 and/or may be used independently from the furthertreatment of main light beam 254. Similarly, the idea of using aplurality of spatial light modulators 114, which may fully or partiallybe transmissive or reflective spatial light modulators 114, may be usedindependently from the idea of imaging by using at least one imagingdevice 262 and/or independently from the idea of re-uniting partiallight beams 266, 270 by spatial light modulators SLM 1, SLM 2. Further,it shall be noted that various additional optical elements may bepresent in the setup of FIG. 17, such as one or more additional transferdevices 126. Thus, as shown in FIG. 17, an additional transfer device126, such as an additional lens system, may be located in front of thestack 166. Further, the optical elements shown in FIG. 17 may fully orpartially have non-reflecting properties, such as using one or moreanti-reflection coatings. Thus, as an example, the half-wave-plates 282,284 each may have appropriate anti-reflection coatings, as well as thetransfer devices 126. Further, modifications of the setup of FIG. 17 aswell as of other setups using one or more imaging devices, such as thesetup shown in FIGS. 10 and 11, refer to the type of imaging devicewhich may be used. Thus, generally, the CCD/CMOS devices shown in FIGS.10, 11 and 17 may generally be replaced by other types of imagingdevices, such as infrared cameras, e.g. thermographic cameras. Thus, inaddition or as alternatives to the imaging devices shown in the figures,infrared cameras may be used, in order to record heat radiation and/orin order to combine a depth picture with an infrared or heatinformation. A thermographic camera may generally be integrated into theoptical system by using wavelength-dependent beam-splitting elements.Thus, as an example, an infrared camera or thermographic camera may beintegrated into the optical detector 110 by separating infrared partiallight beams off the incoming light beam 136 by usingwavelength-selective beam-splitting elements, such as infrared beamsplitter or a hot plate. This setup of the optical detector 110 maygenerally be useful for tracking living beings, such as for gamingapplications. The same modifications as discussed with regard to FIGS.10, 11 and 17 may as well be applied to other setups of the presentinvention, such as the setup of the optical detector 110 as shown inFIG. 18, which will be discussed below.

In FIG. 18, a modification of the setup of the optical detector of FIG.10 is shown. Thus, generally, reference may be made to the disclosure ofFIG. 10 above. Thus, based on the W-shaped setup of FIG. 10, the setupof FIG. 18 contains additional reflective elements 286, 288 locatedwithin the first and second partial beam path 194, 196. Thus, first andsecond partial light beams 198, 200 may be deflected by these reflectiveelements 286, 288, which may be or may comprise one or more mirrors.Thus, in the optical setup of optical detector 110, lens systems, ase.g. contained within the optional additional optical elements, e.g.202, 204, typically require some considerable space. Still, in mostcommercial reflective spatial light modulators 114, the angle ofreflection is limited and rather small. Consequently, a placement oflens systems of incoming light beams in close proximity to the lenssystems may be located in front of the stack 166 and/or in front of theimaging device 256 and may not be feasible in the setup of FIG. 10. Byusing the additional reflective element 286, 288, additional space maybe gained, for the purpose of the placement of additional opticalelements 202, 204, specifically in front of the longitudinal opticalsensor such as the FiP-sensor and/or in front of the imaging device 256.

Specifically, the at least one reflective element 286, 288 may compriseat least one mirror. The at least one mirror may be or may comprise atleast one planar mirror. Additionally, or alternatively, the at leastone reflective element 286, 288 may as well comprise on or more curvedmirrors, such as one or more convex and/or concave mirrors. Thus, one ormore lenses may be replaced by one or more curved mirrors. Consequently,optical detector 110 may even replace one or more lenses by curvedmirrors, in order to save additional space, reflective elements 286, 288each may have focusing properties in order to focus partial light beams198, 200, respectively, onto the longitudinal optical sensor stack 166and/or onto the imaging device 256.

In FIG. 19, a schematic setup of an optical detector 110 to be used as alight-field camera is shown. Basically, the setup shown in FIG. 19 maycorrespond to one or more of the embodiments shown in FIG. 3 or 4 or anyother of the embodiments shown herein. The optical detector 110comprises at least one spatial light modulator 114 and a stack 166 ofoptical detectors 110, preferably large-area optical sensors 156, morepreferably transparent optical sensors 158. As an example, organicoptical sensors 160, such as organic solar cells, specifically sDSCs maybe used. In addition, the optical detector 110 may comprise at least onetransfer device 126 such as at least one lens or lens system, adaptedfor imaging objects 124. Additionally, the optical detector 110 maycomprise at least one imaging device 256, such as a CCD and/or a CMOSimaging device.

As outlined above, the optical detector 110 in the embodiment shownherein is suited to act as a light-field camera. Thus, light-beams 136propagating from various objects 124, symbolically denoted by A, B and Cin FIG. 19, are focused by the transfer device 126 into correspondingimages, denoted by A′, B′ and C′ in FIG. 19. By using the stack ofoptical sensors 116, in combination with the above-mentioned action ofthe spatial light modulator 114, a three-dimensional image may becaptured. Thus, specifically in case the optical sensors 116 areFiP-sensors, i.e. sensors for which the sensor signals are dependent onthe photon density, the focal points for each of the light beams 136 maybe determined, by evaluating sensor signals of neighboring opticalsensors. Thus, by evaluating the sensor signals of the stack 166, beamparameters of the various light beams 136 may be determined, such as afocal position, spreading parameters or other parameters. Thus, as anexample, each light beam 136 and/or one or more light beams of interestmay be determined in terms of their beam parameters and may berepresented by a parameter representation and/or vector representation.Thus, since the optical qualities and properties of the transfer device126 are known, as soon as the beam parameters of the light beams 136 aredetermined by using the stack 166, a scene captured by the opticaldetector 110, containing objects 124, may be represented by a simplifiedset of beam parameters. For further details of the light-field camerashown in FIG. 19, reference may be made to the description of thevarious possibilities given above.

Further, as outlined above, the optical sensors 116 of the stack 166 ofoptical sensors may have different wavelength sensitivities. Thus, thestack 166 may, besides the optional imaging device 256, comprise twotypes of optical sensors 116. This possibility is schematically shown inFIG. 20. Therein, a first type 290 and a second type 292 of opticalsensors 116 is provided in the stack 166. The optical sensors 116 of thefirst type 290 and the second type 292 specifically may be arranged inan alternating fashion along the optical axis 128, as shown in FIG. 20.The optical sensors 116 of the first type 290 may have a first spectralsensitivity, such as a first absorption spectrum, such as a firstabsorption spectrum defined by a first dye, and the optical sensors 116of the second type 292 may have a second spectral sensitivity differentfrom the first spectral sensitivity, such as a second absorptionspectrum, such as a second absorption spectrum defined by a second dye.By evaluating sensor signals of these two types of optical sensors 116,color information may be obtained. Thus, in addition to the beamparameters which may be derived, as explained above with reference toFIG. 19, the two or more types of optical sensors 116 allow for derivingadditional color information, such as for deriving a full-colorthree-dimensional image. Thus, as an example, color information may bederived by comparing the sensor signals of the optical sensors 116 ofdifferent color with values stored in a look-up table. Thus, the setupof FIG. 19, by implementing the color recognition as shown in FIG. 20,may be embodied as a full-color or multicolor light-field camera.

As outlined above, the optical detector 110 may further comprise one ormore time-of-flight detectors. This possibility is shown in FIG. 21. Theoptical detector 110, firstly, comprises at least one SLM detector 294,including the SLM 114 and the stack 166 of optical sensors 116,optionally including an imaging device 256. For details of potentialsetups of the SLM detector 294, reference may be made to the embodimentsshown in e.g. in FIG. 3 or 4 or other embodiments of the opticaldetector 110. Basically any setup of the optical detector 110 asdisclosed above may also be used in the context of the embodiment shownin FIG. 21.

Further, the optical detector 110 comprises at least one time-of-flight(ToF) detector 296. As shown in FIG. 21, the ToF detector 296 may beconnected to the evaluation device 120 of the optical detector 110 ormay be provided with a separate evaluation device. As outlined above,the ToF detector 296 may be adapted, by emitting and receiving pulses298, as symbolically depicted in FIG. 21, to determine a distancebetween the optical detector 110 and the object 124 or, in other words,a z-coordinate along the optical axis 128.

The at least one optional ToF detector 296 may be combined with the atleast one SLM detector 294 in various ways. Thus, as an example and asshown in FIG. 21, the at least one SLM detector 294 may be located in afirst partial beam path 300, and the ToF detector 296 may be located ina second partial beam path 302. The partial beam path 300, 302 may beseparated and/or combined by at least one beam-splitting element 304. Asan example, the beam-splitting element 304 may be awavelength-indifferent beam-splitting element 304, such as asemi-transparent mirror. Additionally or alternatively, awavelength-dependency may be provided, thereby allowing for separatingdifferent wavelengths. As an alternative, or in addition to the setupshown in FIG. 21, other setups of the ToF detector 296 may be used.Thus, the SLM detector 294 and the ToF detector 296 may be arranged inline, such as by arranging the ToF detector 296 behind the SLM detector294. In this case, preferably, no intransparent optical sensor 164 isprovided in the SLM detector 294. Again, as an alternative or inaddition, the ToF detector 296 may also be arranged independently fromthe SLM detector 294, and different light paths may be used, withoutcombining the light paths. Various setups are feasible.

As outlined above, the ToF detector 296 and the SLM detector 294 may becombined in a beneficial way, for various purposes, such as forresolving ambiguities, for increasing the range of weather conditions inwhich the optical detector 110 may be used, or for extending a distancerange between the object 124 and the optical detector 110. For furtherdetails, reference may be made to the description above.

In FIG. 22, a modification of the embodiment of the optical detector 110and the camera 168 of FIG. 18 is shown. The setup widely corresponds tothe setup of FIG. 18, so for most parts reference may be made to thedescription of FIG. 18. The light beam 136 may enter the detector 110via a first lens 306 which may form part of the transfer device 126. Thedetector 110, as an example, in this embodiment as well as otherembodiments may comprise a casing 308, and the first lens 306 may forman entry lens.

Having passed the first lens 306, optionally, as in the setup of FIG.17, an imaging partial light beam 310 may be split off by abeam-splitting element 206 which, in this case, may form a firstbeam-splitting element 250. The imaging partial light beam 310 may beanalyzed by at least one imaging device 256, as in FIG. 17, with orwithout an additional lens. In this regard, reference may be made to thedescription of FIG. 17 above.

The remaining main light beam 136 transmitted by the firstbeam-splitting element 250 is split up into first and second partiallight beams 198, 200, as in FIG. 18, by the reflective spatial lightmodulator 114, the first and second partial light beams 198, 200propagating along first and second partial beam paths 194, 196,respectively.

The optical setup of the first and second partial beam paths 194, 196,in the embodiment shown in FIG. 22 is slightly modified as compared tothe setup of FIG. 18. Thus, firstly, both partial beam paths 194, 196may contain optical sensors 116 configured as FiP sensors, i.e. sensorsexhibiting the above-mentioned FiP effect. As outlined above, an imagingfunction may be performed by splitting off the imaging partial lightbeam 310 and analyzing the site being by using imaging device 256.Consequently, optionally, both partial beam paths 194, 196, large-areaoptical sensors 116 may be used.

Generally, transparent optical sensors 158 are less sensitive thanintransparent optical sensors 164. The setup of the detector 110depicted in FIG. 22 allows for reducing the number of transparentoptical sensors 158, such as by using only one transparent opticalsensor 158. Thus, in the exemplary embodiment shown in FIG. 22, at theend of the second partial beam path 196, and intransparent opticalsensor 164 is placed, such as an intransparent FiP sensor. At the end ofthe first partial beam path 194, a combination of optical sensors 116may be placed, having one transparent optical sensor 158, followed by anintransparent optical sensor 164. Both the transparent optical sensor158 and the intransparent optical sensor 164 may be embodied as FiPsensors. Consequently, the setup of FIG. 22 may contain only onetransparent optical sensor 158.

Generally, most preferably, both the reflective spatial light modulator114, such as the DLP, and the optical sensors 116 are orientedperpendicular to the incoming light beam 136 in their respectivepositions, i.e. are oriented perpendicular to a local optical axisand/or are oriented perpendicular to the main direction of incominglight. This is generally due to the fact that a picture of only onefocal plane should be reflected by the spatial light modulator 114and/or detected by the at least one optical sensor 116. Still, thispreferred setup generally is impeded by the technical challenge that theangle of deflection of the spatial light modulator 140 is generallyrather small. Thus, as an example, a deflection by a DLP, relative to anoptical axis 128 (such as an angle α or β in FIG. 22), typically is therange of 10° to 20°. This constraint, however, generally does not allowfor placing both the spatial light modulator 114 and the optical sensors160 perpendicular to the local optical axis.

In order to overcome the technical challenge, generally, in thisembodiment or other embodiments, specifically embodiments having aW-shaped beam path, additional optical elements 202, 204 may be used,which are adapted to provide appropriate deflection and/or beam shaping.Specifically, as shown in FIG. 22, asymmetric lenses 312 may be used inthe first and second partial beam paths 194, 196. These asymmetriclenses 312 are asymmetric with regard to the local optical axis and,thus, are tilted towards the incoming light beam, thereby deflecting thelight. Consequently, the plane of the asymmetric lenses 312 and theplane of the optical sensors 116 at the end of the partial beam paths194, 196 are not necessarily parallel. Thus, generally, in theembodiment shown in FIG. 22 as well as other embodiments of the presentinvention, one or more symmetric lenses perpendicular to the localoptical axis may be used and/or one or more asymmetric lenses which aretilted towards the local optical axis.

The setup shown in FIG. 22 thus provides several advantages. Thus,firstly, by using the asymmetric lenses 312, the above-mentioned designconstraints resulting from the small angle of deflection of typical DLPsmay be overcome. Further, the setup reduces the number of transparentoptical sensors 158 and improves the usage of light that is reflected bythe spatial light modulator 114, since deflections in both directionsare considered. The use of additional mirrors and the positioning of thereflective spatial light modulator 114 perpendicular to the optical axis128 allow for using a large variety of optical elements and transferdevices 126 such as lens systems, objectives or other optical elements,specifically for shaping the incoming light beam 136.

The setup of the optical detector 110 and the camera 168 as shown inFIG. 18 or 22 may further be modified in various ways, some of whichwill be explained with respect to FIG. 23. In this Figure, a setup of anoptical detector 110 and a camera 168 is depicted which widelycorresponds to the setup of FIG. 22. Still, the embodiment comprisesseveral optional modifications.

Thus, firstly, the transfer device 126 and/or the additional opticalelements 202, 204 in the partial beam paths 194, 196 may containadditional and/or alternative optical elements. Thus, as an example, afield lens 314 may be placed in front of the spatial light modulator 114such as in front of the DLP. By using this field lens 314, an image onthe spatial light modulator 114 may be modified, and/or a size of animage and/or a size of a light spot on the spatial light modulator 114may be modified or corrected.

As an additional or alternative modification of the setup, thereflective elements 286, 288 may be modified. Thus, one or both of thesereflective elements 286, 288, which specifically may be embodied asmirrors, may be flat and planar reflective elements. Alternatively, oneor both of these reflective elements 286, 288 may be embodied non-planaror curved. Consequently, one or both of these reflective elements 286,288 may comprise one or more curved mirrors 316. Thereby, the beamproperties of the partial light beams 198, 200 may be modified, such asby focusing and/or defocusing these partial light beams 198, 200.

Further, additionally or alternatively, the additional optical elements202, 204 may contain one or more apertures or diaphragms, as outlinedabove. This includes the possibility that so-called inverted aperturesare used. As used herein, an inverted aperture is aperture whichcomprises one or more openings other than simple hole-shaped openings.Specifically, as depicted in FIG. 23, one or more inverted apertures 318may be provided in the partial beam paths 194, 196 which block a centralpart of the partial light beams 198, 200. Specifically, this centralpart of the partial light beams 198, 200 may not be focused and,therefore, may not be adapted to give depth information and, thus, maynot contribution to gaining information about a longitudinal coordinate.Consequently, this part of the partial light beams 198, 200 may beblocked by using one or more Inverted apertures 318. It shall be notedthat other types of apertures may be used in order to block unwantedparts of the light beam 136 or of one or more partial light beamsderived thereof.

As outlined above, in some embodiments, it might be preferable if the atleast one optical sensor 116 comprises an array of 2×N sensor pixels.Thus, these types of pixelated optical sensors 116 may provideadvantages regarding manufacturing and/or evaluation of signals. Anexample of an embodiment of an optical sensor 116 having 2×4 sensorpixels 320 is shown in FIG. 24. For the general setup of the opticalsensor 116, as an example, reference may be made to WO 2012/110924 A1,such as to FIG. 2 and the corresponding description, and/or to WO2014/097181 A1, such as to FIG. 4a and the corresponding description.

In FIG. 24, only a transparent first electrode 322 of a layer setup ofthe optical sensor 116 is shown which is, as an example, made of atransparent conductive oxide (TCO) such as fluorinated tin oxide. Thefirst electrode 322 is split into a plurality of electrode fields 324,such as by laser patterning and/or by using lithographic techniques. Theelectrode fields 324 form an array of 2 rows and 4 columns, i.e., inthis example, a 2×4 array. As the skilled person will recognize, adifferent number of columns may be used, such as 2, 3, 5, 6, 7 or morecolumns. Each electrode fields 324 may be contacted by an electricalcontact 326, such that the first row and the second row are electricallycontacted from opposing sides, with the electrical contacts 326 beinglocated at an outer rim of the optical sensor 116.

The first electrode 322 and the electrode contacts 326 may be depositedon a transparent substrate such as a glass substrate. On top of thefirst electrode 322, the remaining layers of the optical sensor 116 maybe deposited, such as by using methods and/or materials as disclosed inone or both of the above-mentioned documents WO 2012/110924 A1 and/or toWO 2014/097181 A1 and/or any other methods or materials disclosedherein. Further, the optical sensor 116 may be encapsulated, as alsodisclosed in one or both of the mentioned documents. The negligiblecross conductivities in the remaining layers generally prevent crosstalk between neighboring sensor pixels 320. Thus, the layer setup of theoptical sensor 116 may contain a common top electrode or secondelectrode (not depicted), such as a silver electrode, contacting allsensor pixels 320. Additionally or alternatively, two or more or evenall of the sensor pixels 320 may be contacted by individual topelectrodes or second electrodes.

An optical sensor 116 having an array of sensor pixels 320, such as a2×N array, is especially suitable for devices as disclosed in thepresent invention, such as for an SLM camera, for various reasons:

-   -   (1) The SLM-camera may modulate each depth-area with a distinct        frequency. At high frequencies, the FiP-signal gets weak. Thus,        only a limited number of frequencies, and thus depth points can        be used. If the sensor is split up into sensor pixels, the        number of possible depth points that can be detected, multiplies        with the number of sensor pixels. 2 sensor pixels results in        twice the number of depth points.    -   (2) As opposed to a normal camera, the shape of the sensor        pixels generally is not relevant for the appearance of the        picture.    -   (3) The frequency range improves, when smaller sensors (or        sensor pixels) are used. In a small sensor pixel, more        frequencies (depth points) can be sensed than in a large sensor        pixel.

In FIG. 25 a setup of an embodiment of an optical detector 110comprising at least one modulator assembly 328 is shown. The setupwidely corresponds to the setup of FIG. 11, so for most parts referencemay be made to the description of FIG. 11. Again, in FIG. 25, the lightbeam 136 enters the optical detector 110 from the left, by passing theat least one transfer device 126, propagating along an optical axisand/or a beam path 208. Subsequently, by one or more beam splittingelements 206 such as one or more prisms, one or more semi-transparentmirrors or one or more dichroitic mirrors, the light beam 136 is splitinto a first partial light beam 198 travelling along a first partialbeam path 194, and a second partial light beam 200, propagating along asecond partial beam path 196.

The first partial beam 198 may travel to the modulator assembly 328. Inthis embodiment, the spatial light modulator 114 is depicted as areflective spatial light modulator, deflecting the first partial lightbeam 198 towards the stack of optical sensors 116. The modulatorassembly 328 comprises the modulator device 118. The modulator device118 may be adapted for periodically controlling at least two of thepixels 134 of the spatial light modulator 114 with different uniquemodulation frequencies. The optical detector 110 comprises theevaluation device 120 performing a frequency analysis in order todetermine signal components of the sensor signal for the uniquemodulation frequencies.

As in the setup of FIG. 11, in the second partial beam path 196, atleast one intransparent optical sensor 164 may be located, such as animaging sensor, more preferably a CCD- and/or CMOS-chip, more preferablya full-color or RGB CCD- or CMOS chip. Thus, as in the setup of FIG. 11,the second partial beam path 196 may be dedicated to imaging and/ordetermining x- and/or y-coordinates, whereas the first partial beam path194 may be dedicated to determining a z-coordinate, wherein, still, inthis embodiment or other embodiments, an x-y-detector may be present inthe first partial beam path 194. Again, as in the setup of FIG. 11,individual additional optical elements 202, 204 may be present withinthe partial beam paths 194, 196.

The modulator device 118 comprises at least one receiving device 330adapted for receiving at least one image 331. In FIG. 26A an example ofan image 331 is depicted. The image 331 may comprise image segments 333.The modulator device 118 comprises at least one image segment definitiondevice 332 adapted for defining at least one image segment 333 withinthe image 331, at least one gray scale value assigning device 334adapted for assigning at least one gray scale value to each imagesegment 333, at least one pixel assigning device 336 adapted forassigning at least one pixel 134 of the matrix of pixels 132 to eachimage segment 333, at least one frequency assigning device 338 adaptedfor assigning a unique modulation frequency to each gray scale valueassigned to the at least one image segment 333 and at least onecontrolling device 340 adapted for controlling the at least one pixel134 of the matrix of pixels 132 assigned to the at least one imagesegment 333 with the unique modulation frequency assigned to therespective image segment 333. One or more of the receiving device 330,the image segment definition device 332, the gray scale value assigningdevice 334, the pixel assigning device 336 and the frequency assigningdevice 338 may be fully or partially comprised by one or more of: amemory device, a processor, a programmable logic such as an FPGA, DLPC,CPLD, ASIC or VLSI-IC.

The modulator device 118 is adapted to perform a method of controllingpixels of at least one spatial light modulator 114. In FIG. 27 anexemplary embodiment of the method of controlling pixels of the at leastone spatial light modulator 114 is shown. In a method step a), referredto as method step 342, at least one image 331 is received. For example,the image 331 may be provided by the intransparent optical sensor 164.The modulator device 118 may comprise at least one image buffer 346adapted for buffering the image 331. Method step a) may be performed bythe receiving device 330.

In a method step b), referred to as method step 344, at least one imagesegment 333 is defined within the image. Method step b) may be performedby the image segment definition device 332. In a method step c),referred to as method step 348, at least one gray scale value isassigned to each image segment 333. Method step c) may be performed bythe grayscale assigning device 334. In a method step d), referred to asmethod step 350, at least one pixel 134 of the matrix of pixels 132 isassigned to each image segment 333. In particular, a matching of thepixels 134 of the matrix of pixels 132 and each of the image segments333 may be performed. Method step d) may be performed by the pixelassigning device 336.

In a method step e), referred to as method step 352, a unique modulationfrequency is assigned to each gray scale value assigned to the at leastone image segment 333. The frequency assigning device 338 may be adaptedto assign the unique modulation frequency based on a predeterminedrelationship between the gray scale value and the unique modulationfrequency. Assigning the unique modulation frequency to at least onegray scale value may be based on a predetermined relationship betweenthe gray scale value and the unique modulation frequency. In particular,a look-up table may be used. The look-up table may comprise a list ofgray scale values and corresponding unique modulation frequencies.

The spatial light modulator 114 may be a bipolar spatial lightmodulator, wherein each pixel 134 has at least two states. Thecontrolling device 340 may be adapted to switch the pixel from a firststate to a second state or vice versa. In particular, the controllingdevice 340 may be adapted to switch the pixel 134 from the first stateto the second state periodically with the unique modulation frequency. Apredetermined maximum frequency may be a maximum frequency f₀/2 forchanging the state of the pixel 134. Feasible unique modulationfrequencies f_(n) for changing the state of the pixel 134 are determinedby f_(n)=f₀/2n, wherein n is a nonzero integer number. The frequency f₀may be a pixel update frequency. For example f₀ may be 24 kHz. Thus, itmay be possible to change a pixel state with a maximum frequency of 12kHz. In FIGS. 28 A and B the frequency generation is depicted. FIGS. 28A and B show switching between states s of a pixel 134 with respect totime in intervals of a scanning time T_(A)=1/f₀.

For example, the time interval between two adjacent states maycorrespond to the scanning time T_(A)=1/f₀. Therein, a first state ofthe pixel 134 has s=1 and a second state has s=0. In FIG. 28 A thefastest possible frequency is shown, wherein in FIG. 28 B the nextslower possible frequency is depicted.

In a method step f), referred to as method step 354, the at least onepixel 134 of the matrix of pixels 132 assigned to the at least one imagesegment 333 with the unique modulation frequency assigned to therespective image segment 333 is controlled. Method step f) may beperformed by the controlling device 340. Method step f) may comprise thefollowing substeps: assigning a counter threshold value to the uniquemodulation frequency, incrementing a counter variable in a stepwisefashion at a predetermined maximum frequency until the threshold valueis reached or exceeded, changing a state of the pixel 134.

The controlling device 340 may be adapted to assign a counter thresholdvalue c to the unique modulation frequency, wherein the controllingdevice 340 may be further adapted to increment a counter variable c in astepwise fashion at the predetermined maximum frequency until thethreshold value is reached or exceeded and to change a state of thepixel 134. The predetermined maximum frequency may be the maximumfrequency f₀/2 for changing the state of the pixel 134. FIG. 28 C showsan embodiment of time dependency of counter variables. In the embodimentshown in FIG. 28 C, the counter variable c may be increased in intervalsof the scanning time T_(A) and/or in intervals of multiple scanningtimes. A low threshold c₁ may result in a short frequency of changing astate of the pixel 134. A high threshold c₂ may result in a longfrequency of changing the state of the pixel 134. A lowest threshold mayrefer to a single interval of the scanning time.

FIG. 26 B shows an embodiment of a blinking pattern 356 generated by thespatial light modulator 114. In this embodiment, the pixels 134 of thespatial light modulator 114 which correspond to the segments 333 of theimage 331 may be switched between states with respect to the assignedunique modulation frequency.

As outlined above, the maximum frequency given by the spatial lightmodulator 114 may limit the number of feasible unique frequencies. In anembodiment, feasible unique modulation frequencies for changing thestate of the pixel 134 may be determined by using Walsh functions. UsingWalsh functions enables availability of a higher number of feasibleunique modulation frequencies for changing the state of the pixel 134compared to using integer divisions as described above, having the samemaximum frequency given by the spatial light modulator 114. Thus, it maybe possible using spatial light modulators 114 having a low maximumfrequency, e.g. a spatial light modulator 114 with a maximum frequencyof 2 kHz.

In step e) to each gray scale value one Walsh function may be assignedto the at least one image segment 333. In case a plurality of segments333 is defined in step b), an appropriate set of Walsh functions may beselected. The Walsh functions may be selected taking into account thetotal number of functions needed and noise between used Walsh functions,wherein the total number of functions needed may correspond to thenumber of segments defined. Preferably, neighboring Walsh functions mayhave as little as possible noise. In addition, Walsh transformation mayuse the entire spectral range such that less noise compared to Fouriertransformation between frequencies may occur. In order to be robustagainst disturbances, Walsh functions may be selected to have a longplateau and thus few zero crossings. FIGS. 29 A to H show a set ofselected Walsh functions. In particular, amplitude A of the selectedWalsh functions as a function of a sample index s_(i) is depicted.

In step f) the at least one pixel 134 may be controlled with a Walshfunction as a unique modulation frequency. As outlined above, a pixel134 may have two states. In case of using Walsh functions the state ofthe pixel 134 may vary not only between an on or off state but the stateof the pixel 134 may be switched according to a pattern given by thecertain Walsh function.

In an embodiment, the evaluation device 120 may comprise at least oneWalsh analyzer 358 adapted to perform a Walsh analysis. Using Walshtransformation instead of Fourier transformations is furtheradvantageous in view of signal processing and signal processing devices.Walsh transformations may be implemented using addition and subtractionprocesses only, whereas using Fourier transformations a digital signalprocessor may be necessary adapted to process floating point numbers.Thus, when using Walsh transformation simpler digital signal processorsuch as a fixed point signal processor compared to digital signalprocessors necessary for performing Fourier transformation may be used.Thus, using Walsh functions and transformation may result in a costbenefit.

Performance of frequency analysis may be affected by noise such thatpresence of noise may result in reconstruction errors and that noise maylimit quality of the reconstruction. Using Walsh transformations lowerreconstruction errors may occur instead of using Fouriertransformations. In FIG. 30 A, the reconstruction quality using Walshtransformation is shown. In particular, the signal to noise ratio SNR in[dB] as a function of the sample index s_(i) is depicted. In FIG. 30 B,a comparison of the reconstruction quality for Walsh transformation,reference number 360, and for Fourier transformation, reference number362 is shown. The relative estimated error r_(s) as a function of thesample index s_(i) is depicted. In addition, for comparison, for each ofthe curves the average deviation is shown. Thus, the reconstructionquality using Walsh transformation may be significantly better thanusing Fourier transformation.

Before performing frequency analysis, a signal may be modified byfiltering processes. Thus, the evaluation device 120 and/or the Walshanalyzer 358 may comprise at least one filtering device 364, adapted tofilter a signal before performing a frequency analysis. In case thesignal, in particular the signal composed of Walsh functions, isfiltered before frequency analysis, coefficients of the Walsh functionsmay be effected. Walsh functions may be distributed over the frequencydomain such that the effect may be different on each Walsh function.This effect on the Walsh coefficients may be taken into account bycalibration of each Walsh coefficient, in particular by amplitudecalibration. Thus, in a first calibration step for each Walsh function,the reconstruction with and without application of filtering processesmay be simulated and may be compared with the original Walsh function.In a further calibration step, the Walsh coefficients may be adjusted.The calibration process may be performed repeatedly, for example toenhance the reconstruction quality. FIG. 31 shows an effect of filteringprocesses on signal reconstruction, whereas the amplitude A is shown asa function of the sample index s_(i). In particular, a comparison of theoriginal signal, reference number 366, signal after filtering, referencenumber 368, and the reconstructed signal is depicted.

LIST OF REFERENCE NUMBERS

-   110 optical detector-   112 detector system-   114 spatial light modulator-   116 optical sensor-   118 modulator device-   120 evaluation device-   122 beacon device-   124 Object-   126 transfer device-   128 optical axis-   130 coordinate system-   132 Matrix-   134 Pixel-   136 light beam-   138 sensor region-   140 demodulation device-   142 result of frequency analysis-   144 data processing device-   146 data memory-   148 light spot-   150 frequency mixers-   152 low pass filter-   154 housing-   156 large-area optical sensor-   158 transparent optical sensor-   160 organic optical sensor-   162 inorganic optical sensor-   164 intransparent optical sensor-   166 Stack-   168 camera-   170 beam dump-   172 full-color spatial light modulator-   174 human-machine interface-   176 entertainment device-   177 scanning system-   178 tracking system-   179 illumination source-   180 Connector-   182 control element-   184 User-   186 Opening-   188 direction of view-   190 machine-   192 track controller-   194 first partial beam path-   196 second partial beam path-   198 first partial light beam-   200 second partial light beam-   202 additional optical element-   204 additional optical element-   206 beam-splitting element-   208 beam path-   210 Car-   212 windshield-   214 front part-   216 headlights-   218 bumpers-   220 side region-   222 passenger doors-   224 Roof-   226 rear part-   228 FiP-sensor-   230 image sensor-   232 capture 2D image-   234 2D image-   236 detect regions-   238 define superpixels-   240 assign modulation frequencies to superpixels-   242 modulate superpixels-   244 z-detection-   246 generate 3D image-   248 refine regions and/or superpixels-   250 first beam-splitting element-   252 first partial light beam-   254 main light beam-   256 imaging device-   258 first partial beam path-   260 Diaphragm-   262 lens system-   264 second beam-splitting element-   266 second partial light beam-   268 second partial beam path-   270 third partial light beam-   272 third partial beam path-   274 back-reflected second partial light beam-   276 back-reflected third partial light beam-   278 common light beam-   280 fourth partial beam path-   282 first half-wave-plate-   284 second half-wave-plate-   286 reflective element-   288 reflective element-   290 first type of optical sensor-   292 second type of optical sensor-   294 SLM detector-   296 time-of-flight (ToF) detector-   298 Pulses-   300 first partial beam path-   302 second partial beam path-   304 beam-splitting element-   306 first lens-   308 Casing-   310 imaging partial light beam-   312 asymmetric lens-   314 field lens-   316 curved mirror-   318 inverted aperture-   320 sensor pixel-   322 first electrode-   324 electrode field-   326 electrical contact-   328 modulator assembly-   330 receiving device-   331 Image-   332 image segment definition device-   333 image segment-   334 gray scale assigning device-   336 pixel assigning device-   338 frequency assigning device-   340 control device-   342 receiving at least one image-   344 defining at least one image segment-   346 image buffer-   348 assigning at least one gray scale value-   350 assigning at least one pixel-   352 assigning a unique modulation frequency-   354 controlling the at least one pixel of the matrix of pixels-   356 blinking pattern-   358 Walsh analyzer-   360 curve, Walsh transformation-   362 curve, Fourier transformation-   364 filtering device-   366 original signal-   368 signal after filtering-   370 reconstructed signal

The invention claimed is:
 1. A method of controlling pixels of at leastone spatial light modulator, the spatial light modulator having a matrixof pixels, each pixel being individually controllable, the methodcomprising the following steps: a) receiving at least one image; b)defining at least one image segment within the image; c) assigning atleast one gray scale value to each image segment; d) assigning at leastone pixel of the matrix of pixels to each image segment; e) assigning aunique modulation frequency to each gray scale value assigned to the atleast one image segment; f) controlling the at least one pixel of thematrix of pixels assigned to the at least one image segment with theunique modulation frequency assigned to the respective image segment. 2.The method according to claim 1, wherein feasible unique modulationfrequencies for changing a state of the pixel are determined by usingWalsh functions.
 3. The method according to claim 2, wherein in step e)to each gray scale value one Walsh function is assigned to the at leastone image segment.
 4. The method according to claim 3, wherein aplurality of segments is defined in step b), a set of Walsh functions isselected, taking into account the total number of functions needed andnoise between used Walsh functions, wherein the total number offunctions needed corresponds to the number of image segments defined. 5.The method according to claim 1, wherein in step f) the at least onepixel is controlled with a Walsh function as unique modulationfrequency.
 6. The method according to claim 5, wherein a state of thepixel is switched according to a pattern given by the Walsh function. 7.The method according to claim 1, wherein step f) comprises the followingsubsteps: f1. assigning a counter threshold value to the uniquemodulation frequency; f2. incrementing a counter variable in a stepwisefashion at a predetermined maximum frequency until the threshold valueis reached or exceeded; f3. changing a state of the pixel.
 8. The methodaccording to claim 7, wherein the predetermined maximum frequency is amaximum frequency f₀ for changing the state of the pixel.
 9. The methodaccording claim 1, wherein gray scale values are color values and/orgray values.
 10. The method according claim 1, wherein step a) comprisesproviding a sequence of images.
 11. The method according to claim 1,wherein step a) comprises buffering the at least one image in at leastone image buffer of the modulator device.
 12. The method according toclaim 11, wherein at least two image buffers are used.
 13. A method ofoptical detection, the method comprising the following steps: modifyingat least one property of a light beam in a spatially resolved fashion byusing at least one spatial light modulator, the spatial light modulatorhaving a matrix of pixels, each pixel being controllable to individuallymodify the at least one optical property of a portion of the light beampassing the pixel, wherein the method of controlling pixels according toany one of the preceding claims is used; detecting the light beam afterpassing the matrix of pixels of the spatial light modulator by using atleast one optical sensor and for generating at least one sensor signal;periodically controlling at least two of the pixels with differentfrequencies by using at least one modulator device; and performing afrequency analysis by using at least one evaluation device and todetermining signal components of the sensor signal for the controlfrequencies.
 14. A modulator device for controlling pixels of at leastone spatial light modulator, the spatial light modulator having a matrixof pixels, each pixel being individually controllable, the modulatordevice comprising: a) at least one receiving device adapted forreceiving at least one image; b) at least one image segment definitiondevice adapted for defining at least one image segment within the image;c) at least one gray scale value assigning device adapted for assigningat least one gray scale value to each image segment; d) at least onepixel assigning device adapted for assigning at least one pixel of thematrix of pixels to each image segment; e) at least one frequencyassigning device adapted for assigning a unique modulation frequency toeach gray scale value assigned to the at least one image segment; f) atleast one controlling device adapted for controlling the at least onepixel of the matrix of pixels assigned to the at least one image segmentwith the unique modulation frequency assigned to the respective imagesegment.
 15. The modulator device according to claim 14, wherein themodulator device is adapted to perform a method of controlling pixels.16. The modulator device according to claim 14, wherein the receivingdevice comprises at least one image buffer.
 17. The modulator deviceaccording to claim 14, wherein one or more of the receiving device, theimage segment definition device, the gray scale value assigning device,the pixel assigning device and the frequency assigning device are fullyor partially comprised by one or more of: a memory device, a processor,a programmable logic such as an FPGA, DLPC, CPLD, VLSI-IC, mixed signalVLSI-IC or ASIC.
 18. The modulator device according to claim 14, whereinthe controlling device comprises at least one oscillator.
 19. Themodulator device according to claim 14, wherein the modulator device isadapted such that each of the pixels is controlled at a uniquemodulation frequency.
 20. The modulator device according to claim 14,wherein the modulator device is adapted for periodically modulating theat least two pixels with different unique modulation frequencies. 21.The modulator device according claim 14, wherein the controlling deviceis adapted to assign a counter threshold value to the unique modulationfrequency, wherein the controlling device is further adapted toincrement a counter variable in a stepwise fashion at a predeterminedmaximum frequency until the threshold value is reached or exceeded andto change a state of the pixel.
 22. The modulator device according toclaim 14, wherein the spatial light modulator is a bipolar spatial lightmodulator, wherein each pixel has at least two states.
 23. The modulatordevice according to claim 14 is adapted to switch the pixel from a firststate to a second state or vice versa.
 24. The modulator deviceaccording to claim 14, wherein the receiving device is adapted toreceive a sequence of images.
 25. A modulator assembly for spatial lightmodulation, the modulator assembly comprising at least one spatial lightmodulator and at least one modulator device according to claim
 14. 26.The modulator assembly according to claim 25, wherein the at least onespatial light modulator is adapted to modify at least one property of alight beam in a spatially resolved fashion, the spatial light modulatorhaving a matrix of pixels, each pixel being controllable to individuallymodify at least one optical property of a portion of the light beampassing the pixel, wherein the at least one modulator device is adaptedfor periodically controlling at least two of the pixels with differentunique modulation frequencies.
 27. An optical detector, comprising: atleast one modulator assembly according to claim 25; at least one opticalsensor adapted to detect the light beam after passing the matrix ofpixels of the spatial light modulator and to generate at least onesensor signal; and at least one evaluation device adapted for performinga frequency analysis in order to determine signal components of thesensor signal for unique modulation frequencies.
 28. The opticaldetector according to claim 27, wherein the evaluation device is furtheradapted to assign each signal component to a respective pixel inaccordance with its modulation frequency.
 29. The optical detectoraccording to claim 27, wherein the evaluation device is adapted forperforming the frequency analysis by demodulating the sensor signal withdifferent modulation frequencies.
 30. The optical detector according toclaim 27, wherein the at least one property of the light beam modifiedby the spatial light modulator in a spatially resolved fashion is atleast one property selected from the group consisting of: an intensityof the portion of the light beam; a phase of the portion of the lightbeam; a spectral property of the portion of the light beam, preferably acolor; a polarization of the portion of the light beam; a direction ofpropagation of the portion of the light beam.
 31. The optical detectoraccording to claim 27, wherein the at least one spatial light modulatorcomprises at least one spatial light modulator selected from the groupconsisting of: a transmissive spatial light modulator, wherein the lightbeam passes through the matrix of pixels and wherein the pixels areadapted to modify the optical property for each portion of the lightbeam passing through the respective pixel in an individuallycontrollable fashion; a reflective spatial light modulator, wherein thepixels have individually controllable reflective properties and areadapted to individually change a direction of propagation for eachportion of the light beam being reflected by the respective pixel; anelectrochromic spatial light modulator, wherein the pixels havecontrollable spectral properties individually controllable by anelectric voltage applied to the respective pixel; an acousto-opticalspatial light modulator, wherein a birefringence of the pixels iscontrollable by acoustic waves; an electro-optical spatial lightmodulator, wherein a birefringence of the pixels is controllable byelectric fields.
 32. The optical detector according to claim 27, whereinthe at least one spatial light modulator comprises at least one spatiallight modulator selected from the group consisting of: a liquid crystaldevice, preferably an active matrix liquid crystal device, wherein thepixels are individually controllable cells of the liquid crystal device;a micro-mirror device, wherein the pixels are micro-mirrors of themicro-mirror device individually controllable with regard to anorientation of their reflective surfaces; an electrochromic device,wherein the pixels are cells of the electrochromic device havingspectral properties individually controllable by an electric voltageapplied to the respective cell; an acousto-optical device, wherein thepixels are cells of the acousto-optical device having a birefringenceindividually controllable by acoustic waves applied to the cells; anelectro-optical device, wherein the pixels are cells of theelectro-optical device having a birefringence individually controllableby electric fields applied to the cells.
 33. The optical detectoraccording to claim 27, wherein the evaluation device is adapted toassign each of the signal components to a pixel of the matrix.
 34. Theoptical detector according to claim 27, wherein the evaluation device isadapted to determine which pixels of the matrix are illuminated by thelight beam by evaluating the signal components.
 35. The optical detectoraccording to claim 27, wherein the evaluation device is adapted toidentify at least one of a transversal position of the light beam and anorientation of the light beam, by identifying a transversal position ofpixels of the matrix illuminated by the light beam.
 36. The opticaldetector according to claim 27, wherein the evaluation device is adaptedto determine a width of the light beam by evaluating the signalcomponents.
 37. The optical detector according to claim 27, wherein theevaluation device is adapted to identify the signal components assignedto pixels being illuminated by the light beam and to determine the widthof the light beam at the position of the spatial light modulator fromknown geometric properties of the arrangement of the pixels.
 38. Theoptical detector according to claim 27, wherein the evaluation device,using a known or determinable relationship between a longitudinalcoordinate of an object from which the light beam propagates towards thedetector and one or both of a width of the light beam at the position ofthe spatial light modulator or a number of pixels of the spatial lightmodulator illuminated by the light beam, is adapted to determine alongitudinal coordinate of the object.
 39. The optical detectoraccording to claim 27, wherein the spatial light modulator comprisespixels of different colors, wherein the evaluation device is adapted toassign the signal components to the different colors.
 40. The opticaldetector according to claim 27, wherein the at least one optical sensorhas at least one sensor region, wherein the sensor signal of the opticalsensor is dependent on an illumination of the sensor region by the lightbeam, wherein the sensor signal, given the same total power of theillumination, is dependent on a width of the light beam in the sensorregion.
 41. The optical detector according claim 27, wherein the atleast one optical sensor comprises at least one optical sensor having alayer setup comprising at least one first electrode, at least onen-semiconducting metal oxide, at least one dye, at least onep-semiconducting organic material, preferably a solid p-semiconductingorganic material, and at least one second electrode.
 42. The opticaldetector according to claim 27, wherein the spatial light modulator is areflective spatial light modulator, wherein the optical sensor comprisesat least one transparent optical sensor, wherein the optical detector isset up such that the light beam passes through the transparent opticalsensor before reaching the spatial light modulator, wherein the spatiallight modulator is adapted to at least partially reflect the light beamback towards the optical sensor.
 43. The optical detector accordingclaim 27, wherein the optical detector contains at least onebeam-splitting element adapted for dividing a beam path of the lightbeam into at least two partial beam paths.
 44. The optical detectoraccording to claim 43, wherein the beam-splitting element comprises thespatial light modulator.
 45. The optical detector according to claim 44,wherein at least one stack of optical sensors is located in at least oneof the partial beam paths.
 46. The optical detector according to claim44, wherein at least one intransparent optical sensor is located in atleast one of the partial beam paths.
 47. The optical detector accordingto claim 27, wherein the optical detector comprises at least one Walshanalyzer.
 48. A detector system for determining a position of at leastone object, the detector system comprising at least one optical detectoraccording to claim 27, the detector system further comprising at leastone beacon device adapted to direct at least one light beam towards theoptical detector, wherein the beacon device is at least one ofattachable to the object, holdable by the object and integratable intothe object.
 49. A human-machine interface for exchanging at least oneitem of information between a user and a machine, wherein thehuman-machine interface comprises at least one detector system accordingto claim 48, wherein the at least one beacon device is adapted to be atleast one of directly or indirectly attached to the user and held by theuser, wherein the human-machine interface is designed to determine atleast one position of the user by means of the detector system, whereinthe human-machine interface is designed to assign to the position atleast one item of information.
 50. An entertainment device for carryingout at least one entertainment function, wherein the entertainmentdevice comprises at least one human-machine interface according to claim49, wherein the entertainment device is designed to enable at least oneitem of information to be input by a player by means of thehuman-machine interface, wherein the entertainment device is designed tovary the entertainment function in accordance with the information. 51.A tracking system for tracking a position of at least one movableobject, the tracking system comprising at least one detector systemaccording to claim 48, the tracking system further comprising at leastone track controller, wherein the track controller is adapted to track aseries of positions of the object at specific points in time.
 52. Ascanning system for determining at least one position of at least oneobject, the scanning system comprising at least one optical detectoraccording to claim 27, the scanning system further comprising at leastone illumination source adapted to emit at least one light beamconfigured for an illumination of at least one dot located at at leastone surface of the at least one object, wherein the scanning system isdesigned to generate at least one item of information about the distancebetween the at least one dot and the scanning system by using the atleast one optical detector.
 53. A camera for imaging at least oneobject, the camera comprising at least one optical detector according toclaim
 27. 54. The optical detector according to claim 27, which isadapted to function as an optical detector suitable for at least oneapplication, selected from the group consisting of: a positionmeasurement in traffic technology; an entertainment application; asecurity application; a human-machine interface application; a trackingapplication; a photography application; an imaging application or cameraapplication; a mapping application for generating maps of at least onespace; a mobile application, specifically a mobile communicationapplication; a webcam; a computer peripheral device; a gamingapplication; a camera or video application; a security application; asurveillance application; an automotive application; a transportapplication; a medical application; a sports application; a machinevision application; a vehicle application; an airplane application; aship application; a spacecraft application; a building application; aconstruction application; a cartography application; a manufacturingapplication; a use in combination with at least one time-of-flightdetector; an application in a local positioning system; an applicationin a global positioning system; an application in a landmark-basedpositioning system; a logistics application; an application in an indoornavigation system; an application in an outdoor navigation system; anapplication in a household application; a robot application; anapplication in an automatic door opener; and an application in a lightcommunication system.